Thanks for the answers. I know, stupid lesson to learn on a live project, as it was the first production project with Publisher after using InDesign for more or less since it was available. You kind of get used to some features 🤔 Educating the advertisers I can try, but this is like relaying a message through 10 people, you cannot say, if the message get's through and you have to deal with constantly changing people, as there usually is more than one ad in this small-town paper. Using Acrobat for me as solution is not an option, as I'm currently on a quest of leaving Adobe behind (quite the task I discovered as photographer and graphics designer). Using the MacOS print engine to create PostScript-Files on the fly is a way I can live with, as I can do this with more or less every file type - I even get ad's sent as Word Documents, and talking to the people doing that proved ineffective so far, after 10 times or so saying the same thing.
Serif delivers excellent work for about 95% of the way, Affinity Photo is an excellent solution as well, if you don't get excessive with layering images. Publisher is a good solution - with it's own set of problems, I'm learning. But currently there is a workaround for most of it. Support for coloured fonts would be nice as well, but that's really a marginal problem.