I never had great luck with a crock pot, and feel I can make things a lot quicker, better and in the same style by using a pressure cooker. Crock pot meats just come out mushy and seem to taste extra greasy. Pressure cookers do soften them a lot but they seem to hold together better and in the case of ribs have a bit of that snap which is so important.
I would crockpot chuck roast all day because that’s what you do. I now put it in a dutch oven at 350 for 4 hours and it comes out so much better.
My husband got a bug in his head to cook ribs in the crockpot (various recipes) and put them under the broiler. Worked out well for us a few times, but one Christmas he put them in with teryaki sauce and let them cook waaaay too long before finishing them in the broiler. We had guests (a rare happening), and the ribs tasted STEWED. Just falling apart. I was so embarrassed after bragging about his mad rib cooking skillz.
Recipies often have fruit component(s) which can also speed the softening.
Especially teriyaki sauce with pineapple juice.