I was getting RSI constantly no matter what ergonomic keyboard I had (MS sculp or whatsitsname was the only one bearable), eventually I got a programmable split keyboard, ZSA Moonlander - RSI immediately gone.
But apparently that was even an overkill, I loved the programmable part so much that I decided to buy Planck for my gaming pc because it's tiny and can fit on my couch-mouse-pad setup... No RSI either! I use it for programming too now. I have a theory that what was hurting me was the need to move fingers to backspace, ctrl, etc. And maybe the staggering as you need to twist your wrists a little all the time. Ortholinear feels just... more sensible, for muscle memory...
From now on I buy only ortholinear programmable keyboards, they are fun, make more sense, and don't get me RSI!