Diki..
Bummer. The one thing none of us wants to do is take time off from playing to heal.
Even after a heart attack, I felt the necessity to play a gig a week later. I knew better than to lift anything and had a music buddy haul in and set up all my gear. But, truth me known, I really should have been home resting.
Sounds like your thumb needs a rest to help the splint help your thumb. Here I would suggest you do as I say..not as I do. But, who am I kidding? I know you will do what you think is necessary and what you hope you can get away with.

Good luck. Hope you heal soon.
Eddie