How many hiding places did your crayfish have to avoid predation?

I think they like piles of "platy" rock the best, but that might be my observation bias since that is where we grabbed the most as kids.

They can also hide in growing vegetation or even logs on the bottom.

I think they are an excellent source of supplemental forage for all types of bass. You might consider dragging a large (non-oak) tree into your pond and anchoring it to the bottom. The crayfish will like the trunk and branches that are on the bottom. Your bass will like the branches sticking up in the water. Your forage fish will like the twiggy cover at the end of the branches until it decays.