As soon as I started my 9-5 job, my wrist started hurting. Fortunately, my workplace bought me some vertical mice and it’s all I needed. It took some getting used to and I can’t play FPSes with them, but I’m not playing those for 8 hours a day, so I just switch back when needed.

It’s not a very Linux-y answer, but VSC does allow you to compare 2 pages for differences. Those pages can be unsaved or saved files.