If they are randomly floating,but not moving in one direction, you could animate it twice, once forwards and once backwards and then mix between the two, using the essence of the technique shown here:
https://cgcookie.com/tutorial/creating-a-looping-cloth-simulation
As for 3.1, it’s still a bit buggy, but Geometry Nodes, for instance, is completely different (don’t even bother learning it in 2.93) and a lot better! For the rest, Cycles render a lot faster, but I did have a few ‘freezes’ when trying to render animations, mainly when I broke off a render and changed some setting and started again.
