I can’t recommend Migadu enough.

It’s running Forgejo.

I’ve been using my own app JamRSS until I switched to Read You because it looked better.

As an example, an old Android project of mine: https://github.com/moritzruth/JamRSS

I showed one screen in both the light and the dark variant to demonstrate that the app generally has support for dark mode.

Where: In the repository, most projects seem to use media or screenshots as the name of the directory.

How often: Whenever a big change happened or many small changes have accumulated.

What: Light theme suffices. I only care about the general look and feel, not about specific colors.

That’s how I would do it for my own projects.

I’ve recently read that Affinity programs now work through Bottles, though I haven’t yet tried it myself.

I use Bromite.

This site gives some reasons: https://manjarno.snorlax.sh/

As someone else already mentioned, using it with a trackpad (for example the Apple Magic Trackpad) is great.