I just installed the app and so far it's working pretty well, though if I'm being honest, I am definitely a little concerned by all the baked-in tracking.

In terms of features I'd be interested in seeing there are three that come to mind:

1. Community icons in compact/ dense views. While Lemmy is still in its infancy, I have to browse c/All most of the time and being able to visually see the community the post is coming for is definitely helpful for browsing.
2. Multiple accounts in one feed. In my opinion, this is one thing that Lift-off has over every different Lemmy app. With so many instances with varying levels of federation, I find being able to browse all my accounts at once to be a very convenient feature.
3. Being able to download to an SD card. I know SD cards are a dying breed, so this is probably low priority for you, but as someone with very low internal storage; but a very large SD card, it's always a welcome feature when I can find it.

Overall I would say this app already shows a significant amount of polish. Hopefully the development can continue even further.