I've used the Microsoft 4000 and its successor the Ergonomic (and the 4000's predecessor as well way back in the day) for over 12 years without issue. I've tried the Redox and the Kinesis split board, both of which resulted in wrist discomfort. I'm currently trying a Dygma Raise, which I suspect is going to end up abandoned as well. I have no idea what the issue is. It seems the MS board's combination of split angle, tent angle, negative tilt (I always use the add-on riser) and key position is just right for me.
How realistic would it be for me to commission someone to make a (probably 3D printed) keyboard which duplicates the MS layout?