I just last week put a 27.5" fork onto a 26er bike. 100 mm travel. Didn't even worry about the added axle-to-crown distance. Just slapped in the new fork, and the ride is great! The front-end is slightly slacker, which given the frame feels like a bonus. I'm happy with the result.

It looks and sounds like your frame will accept a tapered fork. Is this the bike you are looking at?

https://www.randombikeparts.com/coll...lx-3-x-10s-new

The specs say:

Frame: Folding Tig Welded 6061 Aluminum, waterbotle mounts, mounts, tapered headtube

So your frame supports a tapered fork. Low-end forks are often not tapered. Hence the adapter.