Not a direct answer to your frame question but trying to provide you with more futureproof options .
I was in a similar situation and i opted for buying a boost frame and buying a boost spacer kit for the wheels.
There appears to two kind of boost kits, the one i chose maintains the non-boosted chainline.
Update and warning on my previous suggestion
I finally got the missing parts for my build and started the final assembly, sadly i ran in to some problems with the spacer solution.
The hi/low adjustment on my derailleur (11speed Shimano di2 XT) will not allow me to compensate for the cassette sitting 3mm further inboards, so now i cant reach the lowest gear on the rear.
I'm considering my options now, as i see it:
* Move all spacing to the NDS and redish the wheel, this will require more spacers for the brake rotor.
* Custom/modified hanger that moves derailleur 3mm inwards (not likely)
* New rear hub and relace the wheel
* New wheel
Feels like my budget build is busting it's seams :/