I don't know if this has been addressed before (and I did look at a glance and found nothing), but here goes.
The Fire Slimes. Keeping them in the Ash Trough is a huge problem. I've had fire slimes (even with the toy removed) jump into the CEILING of the Cave area where I keep them and out of my trough all the time. I only have 5, which considering they're like puddles, is the right number of those to have (with duckie), so it seemed right.
And... they're constantly getting out. It feels like I can't leave them alone for one second!
So here is my suggestion: please make some walls similar to the other corrals for the Incinerator. An upgrade for them when you buy the Ash Trough, or after you do, or something, please. It would help tremendously. I don't want to lose my babies, and I don't think anyone else does either.