I have added a few input methods in System Settings -> Keyboard -> Input Methods. After that, I would expect the iBus daemon to be auto-started upon boot or login, however I still need to manually start it. I've been doing so via the button in System Settings -> Keyboard -> Input Methods, but there should be a better way?
I found another answer (https://elementaryos.stackexchange.com/a/5313/15156) which mentioned adding ibus-daemon -drx
as a custom command in Settings > Applications > Startup. Is this still the best solution in Odin?