VANKEY Lump Charcoal Fire Basket with Removable Divider Charcoal Basket for Kamado Joe Classic Series, Large Big Size Green Egg Stainless Steel Grill Ash Baskets

I guess something I hadn't though of, is the ash just getting stuck on the iron grate at the bottom of the grill, is that what you're using the scraper on? I swapped to a charcoal basket, and ditched the iron grate, pretty much immediately. That might be the difference here. I think I remember reading about that grate causing airflow issues before I got mine. That's probably also why the Classic 3 comes with a charcoal basket out of the box. It makes it easier to clean out between cooks too. I was reading it like your ash removal tray was completely full. If it's the ash removal tray that's full, replacing the bottom tray system with a removable ash basket should give you a lot more room. Using both a charcoal basket and an ash bucket will give you best results also with improving airflow too.