To add to the discussion, as someone owning R5 caps, I thought I'd share some pictures. Please forgive me my nails, yes I bite them, we all have some bad habbits this is mine. Well that, and chocolate desserts
Anyway, first pic is how you -should- type according to all the doctors and stuff. So keep your wrists elevated, don't let them rest. If you watch the angle of my thumb it's really not that bad to press a R5 key. I wouldn't call it worse than a R4 but your experience may vary.
Second pic is using a wrist rest. It's not as good, but still doable and personally I don't expect al of issues for people. However, I'm not sure I would like it on a 40% keyboard over a long period of time when I need to acces layers a lot.
3rd pic is worst way to type, wrists laying on the table in a very uncomfortable angle.
And lastly, a side-by-side comparison. Black one is R4, white one is R5.