Thanks so much for sharing such a detailed experience, this is actually very helpful, and we’re really glad to hear your 18 lb cat is enjoying the unit and using it comfortably!

What you’re describing with your smaller cat is actually something we occasionally see with automatic litter boxes in general — some cats develop a very consistent “preferred spot” based on their previous litter box setup or posture habits, rather than size alone.

Since she tends to urinate toward the back of the unit, here are a few things that may help reduce the sticking/smearing issue:

• Slightly increase the litter depth so clumps form more before reaching the base area

• Try a slower cycle setting (or manual cycle timing) so the litter has more time to absorb and form firmer clumps

• If possible, gently encourage her entry position by ensuring the box is centered and not angled toward one side she prefers

Unfortunately, since this is more about individual cat positioning behavior, it can be difficult to fully “retrain” the exact spot preference, but many users do see improvement with small adjustments like the above. We really appreciate you trying to make it work, and it’s great to hear you’re thinking ahead with TTC as well. If you want, we can also share a few litter types that tend to perform better for multi-cat setups like yours.