How to take math finals with dislocating thumbs?

Sorry, I am not a med student. But I figured some of you might had similar experiences and could offer advice. :)

I am close to finishing my bachelors degree in Economics. Unfortunately I started having problems with my thumb joint (frequent dislocation which severely impairs my ability to write). (Ehlers-Danlos hypermobile type)

Last year I wasn't able to do finals that involved extensive calculations: The pace expected at the exam is high, even for non disabled students. Yay for me taking the most mathematically involved track within economics. (Sarcasm)

My university does not have a solution for taking tests yet as the standard one they provide is having 30+ minutes of extra time or getting an extra resit, while I am impaired with writing for longer than 30 minutes (while all writing is horrendously painful, I lose grip/strength after 30 minutes).

Did anyone have similar problems with taking tests and what solutions did you get?

Switching programs/tracks is not a solution as I only have a few courses left and funding is running out. Unfortunately, typing-out mathematics is also an unrealistic option when doing derivations.

Thank you so much for sharing your advice!