I have a perfectly good nick pike 454 and some nice sids and pretty much every thing for a full build

So 140mm or 100mm

All I know of is the Coptic bfe….any others any more Xc? Any full Sus or is it all 650 / 29

You could just put all your bits on a 650b frame. If you pick one with a highish BB you might improve it, dropping it on 26 inch.

Depends most 650 bikes are boost spacing, are the hubs on your 26″ wheels boost?

Curtis still build XC 100/120 frames, I believe. Really good 26” steel frame.

Yeh coptic are good.

Banshee Spitfire does 26 or 650b. There’s a nice frame in the classifieds now that I had half an eye on myself.
Edit: you would prob need to buy the 26 dropouts for it.

Production privve Shan is able to run 26inch wheels with a change of dropouts

I wouldn’t buy a new 26 frame.
There must be loads of decent 2nd hand frames about. I have a small orange evo4 (retro!)frame for instance .
😉

All I know of is the Coptic bfe

That would be the Orthodox choice.