On the surface, this looks like a 50% more expensive Flashlight. Let me draw your attention to the three major differences between them:

Cryptographic Cypher lets you choose to, instead, spend a use on a investigation instead of a one, at the cost of making the shroud 1 higher.

Cryptographic Cypher uses secrets, not supplies.

Cryptographic Cypher exhausts after use, while Flashlight does not.

The first point is important for people with high intellect that would normally not take Flashlight, which is most Seekers. Getting 3 additional investigates that also potentially dodge attack of opportunity definitely has value, especially in solo where clues are distributed less tall and more wide (where Ursula Downs excels). It should be noted that Trish Scarborough can turn that into 3 investigates AND evades. Of course, this bares similarity to Fingerprint Kit, which is likely better compression at higher counts at +1 advantage instead of -1. But if you're able to consistently cycle through skill cards (especially Deduction) and commit high enough, the skill value shouldn't be an issue, and Seekers are the best at doing that to begin with (hello Practice Makes Perfect and Mr. "Rook").

The second point means you wont be able to reload this the same way as Fingerprint Kit or Flashlight, say by using Emergency Cache. You have to use Eldritch Sophist, or Truth from Fiction, or Astounding Revelation.

The third point is that this exhausts after use, meaning that you can't chain in one turn (unless you're "Ashcan" Pete). You'll have to spread its uses over several turns.

The odd thing about the card is that it still lets you use it functionally as a slightly slower Flashlight, which I'm not fully sure why someone who took it for the first function would ever want to use the second, or vice versa why anyone who would take it for the second wouldn't just take Flashlight instead (which these days includes lots of Survivors who now run Old Keyring anyway). I think, overall, this is mostly a true solo card, intended to conserve actions (net 2, though keep the costs in mind) and have that little bit of flexibility that might matter on a particularly difficult location that you only have yourself to rely on to clear. Again, Trish Scarborough might like both functions of the card- the former for dodging AoOs, and the latter for helping enable a "succeed by" test that Rogues often like to perform to refresh themselves.

So the other review did not mention that this card combos so well with The Skeleton Key. This isn't my idea but I saw in a deck guide that Skeleton Key sets the shroud to 1 and you can use the fast action on this card and not have to add 1 to the shroud of the location.

This card feels similar to fingerprint kit though a good bit worse. It slightly accelerates your clue gathering at the expense of a hand slot and a fairly pricey asset. This makes you take more tests and increases the difficulty of one of those tests instead of making it easier. I already don't use fingerprint kit much because of the high cost, though I think it can be good especially if reloaded with Emergency Cache (3). Will be curious to see if this receives any upgraded versions because as is it's quite lackluster. I'm very unsure why the second ability even exists if not for an upgraded version to make it much better (like setting the shroud to 0).