That is an excellent tip, the recipe to caramelize the onions in the crockpot would save a lot of trouble (and heat!)

My father, years ago, was in Boston and found out the formerly world famous baked bean recipe of Durgin Park. He must have missed the part when they told him you had to boil the navy beans for three minutes then let them sit over night, as he would put the beans in the oven for days at a time and they would not tenderize. After he finished tearing his hair out, he went and bought good old B&M baked beans and abridged the recipe using them.

Beans, on top and bottom, bacon, green peppers, onions and celery in the middle, with dried mustard and ketchup, and lots of ketchup on top. To me, it's a baked item, preferably in a stonewear.