What I liked about the old setup was that I could be in the Page Rules for one domain, then go to the top and live-search to switch to another domain. This is impossible now. Only the other domains in the “Websites” menu are available without hopping through the menu again.
Seems like this has been recently re-introduced and working at least for me.
I can “type and search a domain again”, and switch to a domain on the exact page while being on the same tab/page on another one (within the same CF account):