Jennie and Mazy cat are both pee shooters but only in the high sided box. If they use the smaller low sided box they squat nice, though sometimes the pee does go over the edge. The low sided liners really are too small so I can't blame them.
I solved the problem of over the edge by putting a layer of the grass litter underneath. This works very well, once a week I lift out the paper liner and check for leaked pee and clean it up if there is any, by simply scooping out the wet grass litter and adding more.
This is done in both paper lined boxes but the other one is already finished and too hard to take apart to show.
...
Anyway one day a while back to my horror I saw Jennie shooting her pee and it was going right over the top of the high sided box to the wall behind! I pulled everything out and discovered a real mess. I can't believe it didn't smell worse. I cleaned it thoroughly and devised a way to catch the extra high pee shooting.
The cardboard doesn't fit tight against the paper liner (to prevent leaks behind instead of running back into the box) so I tuck little wads of folded cardboard behind to give it a more custom fit.
Jennie and Mazy cat seem to really enjoy drilling their pee against the cardboard, in fact they go even higher now that the cardboard is in there.
Jennie uses that box exclusively.
Mazy never stands up and shoots like that in the low sided box.
Queen Eva generally uses the grass litter box for pee and the large high sided box for poop. She is the only one who uses the grass litter box at all.
Paper liners and new litter are replaced every 4-5 weeks. this being 4 1/2 weeks today.