250# really isn't that much.

I've weighted as much as 250#, used to be a masher and not a spinner, and got 35 years out of a Mavic MA40 rim with 36 straight gauge DT swiss spokes. Machine built wheel no less. Only reason I replace the wheel is a broken chain ate half the spokes.

I don't like to run anything less than 36 spokes on the rear wheel. Always had good luck with that. I typically run double butted spokes.

My gravel bike does have a 32 hole disc brake rear wheel. Had multiple issues popping spokes. Rebuilt the stock rim with quality spokes and still had trouble popped spokes. Finally replaced the stock rim with a 32 spoke Mavic A719 rim and a combination of Alpine III spokes on the drive side and double butted on the non-drive side. That is thankfully holding up.