I’m not sure if this will be helpful to you. I have a great deal of pain in my CMC - the joint at the base of thumb nearest the wrist. I’ve used compression gloves and thumb braces in the past with some relief. What really helps me significantly is steroid injections directly into the joint. My doc does them guided by ultra sound. The joint aches for about 24 hours, then I get relief and increased function for 4-6 months. I’ve also had the knuckle of my index finger injected. Keeping these 2 joints pain free really increases my grip and strength. Hopefully, a good ergonomic mousr is sufficient for you, but this may be an option if your thumb worsens, Jo