Can I recommend something for your litter issues?
We had the same issues as above, my issue would be the small trays would last a day or so, the big white tubs were marginally better but still somehow managed to get out of the box. And the smell
We ended up with a dog kennel type enclosure with a doggy door that worked brilliantly. Not only did it keep all the poop inside but the smell problem was significantly better. The litter bags are never big enough but this made life much easier for us. Doesn't stop the occasional slippage especially from the younger one who always needs a clean litter
I it appears I have traded for dealing with one kind of poo to another