I agree on the R5 stuff, if it were me I’d include the r4 versions to the base kit and r5 to the r0 kit. That way you keep the base kit down, but still have the option if it sells well. I also am not a big fan of how it looks in photos even if I do enjoy typing on r5. So I could see wanting both.
Regardless, the way it is now greatly hurts compatibility with any non traditional bottom row board which isn’t exactly a rarity these days. Plus, from my understanding r5 keys cost more and for compatibility this set is adding an entire second bottom row to the base.