my shrek/pool size brother in law was able to fit in every ride when we went last week.
he carries his wait on his hips a bit more and has a big belly (yes he told me i could say this)
however he did say a few made him feel uncomfortable (forbidden journey, rip ride)
hagrids' was fine for him on the bike
mummy and gringotts he had to sit in a specific row (not the front) and the CM needed to press down for a certain point to make sure he would be safe.
hulk we had to wait for a specific row that has a modified constraint that he was able to fit in
dudleys', pluto, transformers, jimmy fallon, despicable me, simpsons, MIB, spiderman, jurassic and kong are fine for him.
definitely watch vlogs for more specifics but also try out the ride vehicle before getting in line.