Steph (TTRPGkids) is doing some amazing stuff not only reviewing educational TTRPGs, but also working with classroom teachers to create TTRPGs for their classes.
I like using homebrew monsters and house rules, but homebrew classes make me a little nervous. If you like them, however, check out these and let me know what you think.
I often see the question of how to run D&D with large groups or classes and I'm not convinced it's a great idea. There are TTRPGs that are set up for that many though. Steph (TTRPGkids) has made a nice list here.
Adventure idea: A group of modrons search for their creator (The Gygax). I think the Barbarian should be the d12 and the wizard the d6 though.
Whilst I love Third Party adventures and homebrew magic items, I've always avoided unofficial classes and races. Flutes Loot recommend these though, so try them out if you're adventurous.