Hey, sorry for the late answer, but I think you might be interested in this:
First of all, as a disclaimer: I'm not a professional front-end developer. I'm usually doing backend stuff and this is the first time I wanted to program a cross-platform desktop app. I spent a lot of time researching and settled on GTK / Libadwaita.
And I actually spent the last months building and packaging the project for every platform. With every platform I mean macOS, Linux and Windows. I strongly recommend doing this with a CI pipeline as there are many specific steps you need to follow.
I will provide a template on Github when I'm finished as well as a more in-depth blog post about all the steps and explanations. The main problem is that most is not documented at all and what's documented is super outdated. So I had to figure out many things by myself. But the actual process, when you know how to do it, isn't even really hard. I'll post the links to the template here when I finished it all but it might still take some months as I currently also have other stuff to do.