I haven’t played around with the buildin apps, but if i remember correctly iX added support for labels a while back, so it should be possible to add traefik labels to iX apps. The Problem from my understanding right now is that you can’t add additional networks, like the required proxy network from techno tim’s traefik tutorial. But if one would install portainer and edit the buildin app via portainer gui, it should be possible to add other networks to iX apps.
But again, i haven’t tried it myself. So i may be completely wrong.
Edit: here’s the implemented feature request [Accepted] Add "Additional Labels" UI to app configuration