The update on Penwiper eating in the dining room is ... there is none. It's been so smooth with him eating in the dining room, there is little to say.
Penwiper has had his serving size trimmed to what he normally actually eats, and we tend to grab anything he occasionally leaves behind to avoid having Billy thinking it's part of the Catzilla buffet. (For historical reasons, while Billy and Whitey always start with their own bowls with Whitey to the right of Billy, they are allowed to swap off with each other.)
We already have decommissioned the library water fountain, and the (under used) library litter box probably goes away this weekend.