Doing Muay Thai with a slightly fked right thumb

Hi, tiny bit of background, I used to do martial arts before COVID (7 years of judo followed by 6 of traditional jujitsu). Started doing some MMA for a couple month after but fucked my thumb on a takedown exercise.

This was 2 years ago and ever since it has never been properly taken care of with a tendonitis flare up earlier this year that led to some real recovery work. Unfortunately despite being technically fully recovered it still flares up sometimes under constraints or shocks.

I will go back to my doc but he does not do Muay Thai so basically what I’m asking is how heavy can the impacts be on the side of the hand blocking kicks or punches?

Thanks to anyone who took the time to read and answer.