I too have performance issues on a fully specced out 2019 16" MacBook Pro (8-core i9, 32 GB, M5500 8 GB graphics) and very small documents. 20 pages and there's already stuttering and a delay of half a second for every second command or so.
In this state, Affinity Publisher is really no alternative to any other publishing tool right now, which is so disappointing. I was ready to make the switch from Adobe because they have their own host of problems. But looking at this mess, they seem to be the lesser evil right now.
