MKC
you can create a application or window rule via the game’s window operation menu’s “more” submenu (can use the equivilant shortcut if full screen or no border) once you open the dialog, the thing you’d be looking to add is “block compositing” set to “force”. it will automatically turn compositing back on once the process is closed
At least for us, notifications aren’t something you can really glance at similarly to app indicators. They’re usually text heavy, only really work for longer tasks for readability (which syncing usually isn’t), and are always obscured behind another popup for persistent notifications. Persistent notifications also take up more space within the notifications popup, rather than a small icon that you can easily glance at to know what’s happening.
As for programs not staying in the task manager, they usually take up less space if open as an app indicator, being able to be passively open but not take up as much space.