Thumb is now at full strength again.
Here is the complete protocol:
Sunday: hurt thumb
Monday: hit again, made it worse. Couldn't even grab my phone without bad pain
Tuesday to Thursday: taped my thumb so the hand was at full rest
Friday to Sunday: started to move the hand again but not grab anything heavy or grip hard. Still slight pain but not much.
Monday to tuesday: hitting wiffle balls of the tee again. Hand was mostly pain free
Wednesday: hit hard balls off tee
Thursday: hit live pitching without problems
So basically 1.5 weeks missed but no pain or weakness anymore. I would definitely recommend this over playing through it and dealing with pain and weakness all season before it can heal in the off season. It is hard to sit around a week but sometimes it has to be done.