In Affinity Publisher I found out you can copy layer effects by simply copying an object (ctrl+c) and then using shift+alt+v on another selected object to paste the effect.
One problem I'm having with Publisher is that linked objects keep resizing and moving when I update them. I'm making hardback covers at the moment, and instead of maintaining 2 completely different files for 10 books I've split the layers into separate files. So, I have the background image with the cover art, and then three files containing the text & logos from the front cover, the spine, and the back cover. These can then be 'placed' onto a different sized background to generate the paperback and hardback covers, which have different size and spacing requirements.
It works, but when I re-export any of those files, everything moves which wrecks the whole document. I'm going to try pasting directly instead of using frames, and that might work. I also had to turn off auto-update of linked content, because half the linked stuff would just disappear. (I've tried linking afphoto files, afpub files and pngs. It's not the file type.)