This is just so frustrating. I have generally been enjoying my time with the Affinity Suite, and Publisher especially is killer software, but missing features like this really make things super difficult to get work done, when Adobe has them and they work.
Sometimes we have to work with graphics we get from outside organizations, and we have no control over quality. Like right now, I have a logo I need to put on a vehicle wrap that's simply a JPG file with a white background. I need to vectorize it and make the whole thing white, so it pops against the colored wrap. And I can't, because this software suite is missing this, IMO, core functionality.
I have now put the logo through vectorize it and convertio and neither can convert it. Which is ironic, because the logo was clearly designed in Illustrator using default brushes. So I can't even re-create it, because I don't have those brushes, either.
Illustrator was so much better in this space, and had the tools needed to get this work done. In an ideal world, you'd be able to get usable vector files from everyone, but that's isn't reality. And Affinity is making this very, very difficult.
If I have to download other software to do stuff like this, I might as well just download Illustrator and be done with it. Which is frustrating, because I much prefer the Affinity suite.
TL;DR: add another vote for adding in vector tracing.