I've tried a few different ergonomic keyboards (never a Kinesis or Maltron, but recently a TECK), but the problem with all of them - for me - is the lack of tenting. It definitely causes me problems, especially when touch-typing.
I have an old, and much-loved Cherry MX5000, which does both variable tenting and split-angle, and my wrist/arm/shoulder problems are much reduced by using it. I actually force the tenting higher, by propping its inner legs on a book, and it works even better.
Of course, if it wasn't staggered, and maybe also had scooped keywells ... I can but dream. AcidFire's Axios project on CrowdSupply is a move in the right direction, imho.