I think it would be neat to not only track watches, but also the type of watch. Wether you watched in a theater, on a streaming service (and which, like Netflix, Disney+ etc, all the JustWatch providers you know). Of course, that should only be optional, default just no metadata. Like with collections.
And to go even further, a possiblility to tag/add metadata for the "type" of content you've seen. Wether you've seen it in 3D, 4DX, Dolby Atmos etc.
Note: I don't think it fits the "List-related Feature Requests", but it seems the best match, haha!