I gave my initial thoughts here but I thought it worth boiling down to a few features I (possibly selfishly) would like to see:

• Lemmy login (and other Threadiverse devices like Mbin/Kbin and perhaps PieFed but the lack of an API may be an issue) - you can already use your login from a number of other Fediverse services.
• Import IMDb lists - you can import Letterboxd ones.

As both features are already running in NeoDB (just for other websites) it should lower the bar for these changes, compared with starting from scratch.

Anything else people want to see?