2. While I am working with GTK4 version 4.6.9, the current version of GTK4 is much higher. Because of this, quite a few things I'm using are already deprecated in newer GTK4 versions. Honestly, I'm not sure how to handle this. I would love to hear your thoughts.
This was exactly my problem when I was implementing GTK2 while GTK1 was the main Lazarus widgetset. Their API changes while you're working on it and stabilizes when a new major is started. So you're always one version behind. I hoped that nowadays it would be more stable, but from your message I fear that not much is changed.