Tried search function, didn't find anything on this...

Will a SRAM Rival GXP (Stages Power Meter) crank arm properly fit a SRAM GX Eagle GXP Boost crank and provide proper Q-factor?

Will a Shimano 105 (Stages Power Meter) crank arm properly fit a Shimano M8000 XT Boost brank and provide proper Q-factor?

I wasn't sure where I could find the specs/measurements, or else I'd have tried to figure this out that way before posting. Apologies beforehand if my exhaustive attempts to find a solution before asking failed despite there already being solutions provided already that I could not see (sorry one more time for asking if it's already been asked--because I know people love to hammer about search functions).

The gist of this question is that I am looking to replace a gravel/road bike for bikepacking/commuting duties with a 27.5+ hardtail bike/frame because it is more versatile (I'd use the funds from selling the gravel bike to build up a nice set of boost 29er wheels for pavement use with the hardtail and keep the stock wheels for trail riding), but I want to be able to bring over the power meter (currently a Rival GXP crank arm on a Force GXP crankset--would like to upgrade the plus hardtail to GX Eagle with part of the funds from the gravel bike sale as well).

I also ask about 105 because my indoor trainer bike currently has a 105 Stages and if I don't upgrade my plus hardtail, I'd just transfer that power meter over because it currently is running Deore M8000.

The hardtail is a 2016 Scott Scale 720 Plus and the gravel bike is a 2016 Jamis Renegade Exile, if that matters at all.

Thanks in advance for any help or advice you can provide!

-Ed