I got a pretty bad case of RSI with that setup, since it encourages one-handed chording (e.g. pressing C-x C-s by holding down your pinkie on Caps Lock while twisting your wrist to tap X then S using other fingers on the same hand). It’s far more ergonomic to do two-handed chording, where you press one key at a time with each hand to the extent possible. For me, that meant using Karabiner Element (Mac) and Keyd (Linux) to map Return to another Ctrl key when held down (in addition to the Caps as Ctrl mapping). Then I can simply hold down Return with my right hand and tap X then S with whatever fingers feel natural on the left hand, without twisting my wrist at all.

Indeed. I had RSI issues very early in my career, and the standard advice by ergonomists was "Use both hands when doing any multi-key sequence". If you're doing Ctrl-C, use the right Ctrl button, and so on.