This was the first game jam I joined and I've had a blast. I've gotten some more experience, learned some new things and had a lot of fun! I just noticed I can still alter and reupload the files I've submitted without any consequences, though. Doesn't that somewhat void the point of making a game in 48 hours :)?
There definitely are other options for community game jams, but it's often up to the facilitators to decide how strict they are going to be on things.
Some game jams have very strict rules about asset sourcing, boilerplate code, submission deadlines, etc. Others are really open about the details and just want to see people make games.
Indeed, we chose itch purely due to it being one of the easiest ways to host a jam. The Super Quantum Mutants however was an exception. They submitted on time, but had issues getting it to accept their game. For some reason itch didn't like their link. I discussed it with them at the time, and I made a special link for them to submit - something game jam hosts can do. I can confirm that their 11 minute late submission was exactly the same as what they tried to submit 2 minutes before time was up.