Practical limits to activity time/duration/length

Hello, next month I will be doing a ultra distance paddle race, 1000ish miles spread over 6-10 days. It consists of 18 paddle hours and 6 mandatory rest hours, per day. My watch is a Fenix 7X SS.

Are there any practical limitations to how long a SUP activity can be? All in its probably going to take 110-140 hours. I'm thinking in terms of how large/number of points a FIT or GPX file can handle before something might crash or get corrupted. I would really hate to get 3 days in and lose the whole thing.

I could end the activity and start a new one each day, but I was planning on just pause/resuming around the breaks to have it all as one activity.

One thing I have noticed after uploading the planned race course to Garmin Connect, it really gets sluggish and slows down my web browser a lot, given the sheer size of the track. Doubly so when Course Points are selected. And that's with a fraction of the number of waypoints compared to a watch recording once a second.

I have already run into the problem of being limited to 200 course points per course. I've played around with trying to split it up into 4-5 chunks but so far its been a pain in the ass to do, and no software out there (Basecamp!) is user friendly enough for me to handle it.

connect.garmin.com/.../112499693

The longest continues activity I have recorded in one shot it ~15 hours and it handled it fine.