The best I can offer is mediocre bro science. I stopped using a computer or any kind of device outside of working hours and (as my condition allowed) I lifted weights. Eventually my grip strength was solid and my pain was minimal. Then i took up brazilian jiu jitsu which requires significant grip strength in a bunch of angles. Fundamentally i believe that thoughtfully only using a keyboard during work and gaining significant grip strength over time gave me a much bigger buffer against RSI.