How long are you looking for?
If you can still get a decent length Reverb in with a 20″ ST then these have a reach of 452 in XL:
Orbea Loki 29
I demoed a large set up 27.5+ (a LTD with the factory brake/bar upgrades) and it was lovely. My first real go on a plus bike and I was blown away, so I wouldn’t discount getting something with clearance for 3″ tyres. Worth giving a go. I went in very cynical but had an amazing ride, flat out down EWS tracks. I think it would also make an amazing 29er, we ordered a demo bike for stock off the back and I have some 29er wheels to fit for testing.
If you aren’t too hung up on the search for reach then my current bike gets a vote:
Zealous Division Mk2
Really fun and nimble, very fast and capable bike.