Have you figured out what you were/are doing that is causing RSI in both forearms? For example, are you bending your wrists while typing (just one example)? This is not a direct answer to your question, but maybe figuring out what is contributing to your RSI can be part of the solution.

I'm not an expert in RSI. I have typed on computers for 10 hours/day for decades and never had a problem, but I also touch-type with correct hand position and play piano regularly, so maybe those things have protected me somewhat. Perhaps something like breaks every 20 minutes or icing your wrists/forearms periodically while working could help reduce your RSI problems.