Help with an XP farm

I’d like an xp farm at my base. (Mycelium island) I love gold/xp farms but firetick is off on this realm and I don’t know if I can get enough iron to fuel it. I’ve seen silverfish farms but I hate the idea of potions.

I have a witch farm(far). I have a fish farm(far). I just need xp on the island.

Maybe some sort of bonemeal and smoker setup? Those seem pretty inefficient though. I’m open to nether options as well. I can get wither skeletons so maybe that would be the best option.

Just looking for some ideas.