At the time of writing (before Hemlock Vale Encounter Cards are added to the database), a rough search shows that 17 treacheries attach to locations and test some skill and 21 treacheries attach to locations and have a // ability, which likely involves a skill test. Combining and eliminating duplicates and duds in both results gives us 18 treacheries that actually has "a skill test on a treachery attached to your location". Add the 2 new "attach to location and test" treacheries from Hemlock Vale (edit: there are 3 but one can usually only be tested from a connecting location) and that gives 20 valid treachery targets for Survival Technique, more or less.

As for locations, depending on search criteria anywhere from ~150 to over 450 turn up so let's just say it's more difficult to give an accurate estimation.

Notably this can boost the basic Investigate test on Searching for Izzie, but given that Jenny cannot actually use Survival Technique without advanced jank and less roundabout ways such as Flashlight (3) or commiting skill cards being available, it's more a curiosity than a legitimate answer to that weakness.

But back to the topic of treacheries from the encounter deck. Even if one may think "Sweet! Now I can get +2/+4 on my Locked Door test!" or likewise, Alter Fate (1) from the same faction takes care of most problems of similar calibre with the same one action and testlessly. So ultimately, my final verdict for the second ability on Survival Instinct is that be glad if it comes up but don't count on it to save your run.

The first ability is where the real meat is at. Being able to recycle the likes of Shrine of the Moirai and Barricade (3) is obviously very good and in the latter case potentially scenario-breaking, but I believe the best "attach to location" event that synergizes with Survival Technique is Breach the Door.

Breach the Door is a decent card that allows monster killers to help with clueing duty in 1-2 locations per game, Now Survival Technique asks: What if you can do it more than twice? Better yet, what if you can use BtD to reduce the shrouds of multiple locations to 0, multiple times per game?
Shed a Light already showed us how broken 0-shroud locations can be and it got instantly chained. But aside from that. a bunch of other cards also interact with shroud, with Lola Santiago being the most prominent example. It is a combo so amazing that it's worth building around, from the econ to repeatedly replay BtD, Farsight to play it fast, ways to tutor for both cards and whatnot.

I think two investigators in particular would want to take a long hard look at the ST-BtD combo:

• Charlie Kane. Has access to both cards and Lola Santiago. Get Bonnie Walsh in play and maybe add an Inspiring Presence to your 0-difficulty investigation test to overwork poor Ms. Santiago into giving you 3 testless clues for free per round. He could have trouble oversucceeding on the Breach test, but hey, that's what his allies are for.
• Kate Winthrop. Has access to both cards as well as Ravenous Myconid (Sentient Strain), Farsight and Barricade (3). When your location's shroud is 0, Myconid can block any non-weakness treacheries you draw even at 0 growth (because 0 shroud is equal to 0 growths and the cancel itself already changes game state). Combine with Barricade (3) to build a command center that's also a literal fortress where nobody except an Elite boss can get in. She can also stack +2s with her Flux Stabilizer to help with the oversuccess.

William Yorick, "Ashcan" Pete (normal and parallel) and Tommy Muldoon can also take this combo (edit: Daniela Reyes can too! Thanks to MrGoldbee for the catch), and could probably play it to decent effect though definitely not as spectacular. Probably involves way too many role changes to be worth it on Lola Hayes though.

This is the only card that can tutor Rituals or Talents, making it very attractive for builds using those.

Especially given the renewed interest in bless/curse, this card can really help find Favor of the Sun/Moon.

I was excited by this card when I first saw it, but having now finished a campaign as Kate I think it’s only okay-ish. At first glance this card looks like clue acceleration that comes with nifty consolation prizes if you don’t hit the +4 test result for the extra clue, but I quickly realized that I overestimated how often I could force the result I wanted. There were plenty of times I wanted to pick up two clues in a single action (very easy to do with other level 0 cards like Deduction or Fingerprint Kit) but test result just didn’t come out the way I needed.

As it turns out, consistently succeeding by exactly 4 is not easy to manage. Steady-Handed expands the range to 3-5 to get the extra clue and Fine Tuning gives you two attempts per turn, but at this point you’re devoting additional assets (not to mention experience points) to an effect that still isn’t guaranteed to pay out when you need it. It’s worth mentioning that none of these cards are Fast.

With any clue acceleration that relies on Investigate checks you can pull the tentacle and fail, and that’s true of Chemistry Set too, but Chemistry Set has the additional problem that there are lots of other tokens you can pull from the bag that will ensure you get absolutely no benefit from the Chemistry Set at all. The most common way to miss out on a Chemistry Set payout is to pull a token with a larger negative value than you were planning for, but it also feels bad to miss out on the extra clue because you pulled a positive token and got a result that’s too successful to provide a benefit. A levelled up Chemistry Set that exhausts after you pull the token would help avoid a lot of wasted activations and feel-bad moments.

Sure, even when Chemistry Set doesn’t pay out you still get the basic clue from the Investigate test, but that would also be true if I hadn’t spent the action and resources to play Chemistry Set in the first place. Even the tool synergies seem underwhelming, since there are a lot Tools that help you investigate and provide more reliable benefits than the Chemistry Set (such as Lockpicks, Old Keyring, Mariner's Compass, Magnifying Glass, Fingerprint Kit and Ice Pick, to name a few).

To be clear, Chemistry Set paid out cards/resources a few times every scenario I played it, and sometimes even helped me pick up extra clues. It isn’t a terrible card and it does explore interesting new territory for Seeker assets. However, even with multiple support cards in play it often didn't pay out when I needed it to. With the notable exception of Kate and her Science synergy, I think Chemistry Set is more of a novelty than a staple.

The basic or specialist-ized versions seem like they reliably give 3 or more wild icons almost all the time if you do a little planning and jumping through hoops. But Survivors have always been able to get lots of wild icons on 1-2 XP skills and occasionally on 0s. This one is solid but not especially exciting as far as that goes.

Mythos-hardened seems pretty bad outside of extremely niche counterplay situations. I rarely want to spend that much XP just to prevent one copy of one treachery from coming back, let alone limiting myself to a subset of traits and requiring a test and locking up an otherwise good card. "Fool me once..." and The Eye of Truth put this to shame.

Nemesis seems okay as multiplayer support (take elite trait for boss fights) or to enable Exploit Weakness, but I have little to say about it. No, the only really interesting part of the card, IMO, is Always Prepared, which lets you return one of these cards to your hand once per round if you draw the right kind of encounter. In one sense, 5 XP feels like a lot to spend on a card with no action compression at all, just to pass tests. On the other, a lot of decks do run multiple 2-3 XP assets that are mainly for skill boosting and test-passing. If we can actually make this trigger at least every other round, it might be worth while.

One nice thing about Always Prepared is that while Nemesis and Mythos-hardened only trigger if you actually commit Grizzled against the encounter card, Always prepared doesn't require you to be testing against the card at all. You get it back in your hand to do whatever you like with as long as you drew the right type of card. I believe it should even work when you draw weaknesses from your own deck, if the traits match.

This will be especially valuable if you have special incentives to commit cards to tests (Sea Change Harpoon), other uses for cards in hand (Wendy Adams, Cornered, Celaeno Fragments), or a tendency to draw extra encounter cards (Kicking the Hornet's Nest, Drawn to the Flame, Nature of the Beast, Nine of Rods).

I can especially see Patrice Hathaway taking this traited with "monster" and some common treachery traits like terror, hazard, or madness. She'll get one in the discard early and pull it back every time she hits a monster in the encounter deck, draws into her personal weakness, or fishes out a treachery, and she can just throw it into an invetigate or away for vioin money. If she misses she can fish with Drawn to the Flame and Nature of the Beast for more matches. "Ashcan" Pete can do most of the same stuff.

William Yorick can go tell others to "Let me handle this!" or take First Watch to make sure he gets his triggers in. (Calvin Wright also gets some of these options).

It's never going to be as viscerally exciting as firing up a Lightning Gun, Seal of the Elders, or The Black Fan, but I think it has enough value to be worth a shot.

The introduction of Survival Technique in the Hemlock Vale set creates new possibilities for all our old favorite traps, especially this customizable beauty. Survival Technique allows you to return one of your cards attached to a location to you hand each turn, which means that you can relocate these traps and keep them going indefinitely. You will definitely want Simple so you don't want actions re-setting them, and may also want the tripwire or improved timer to cut down on the resource cost of frequent replays, although honestly you will probably move around enough that you rarely need to reset one without moving it anyway.

That 1 cost to redeploy could become negligible anyway if you're running Dark Horse or Madame Labranche or On Your Own or The Fool • 0.

If you manage to find both you can even stack them to give all non-elites a -2 difficulty, and if you make them poisonous you can even deal some damage over time to the elites so the guardian can't say you didn't help at all.

At one point there were FAQ answers floating around implying that Survival Technique would boost basic investigates, which I thought might make it enough of a staple to reshape the playing field. As things stand, the difficulty of finding and playing a 2xp talent and then both copies of your ~level 2 trap is significant enough (none of them have easily tutored for traits) that the juice probably isn't worth the squeeze unless you have a lot of other pieces that interact with it.