I was also fine with FF 156 version of Nova where compact mode was really compact with vertical tabs and rounding was restrained enough. With FF 157 they have added more padding to vertical tabs to compensate for close tab icon on rounded favicons, menu borders are so rounded they clip menu items, PIP min size lock has been removed so you can minimize it to a popsicle, and so on. It seems like they skipped a lot of QA.