Seems like an interesting effort. A developer is building an alternative Java-based backend to Lemmy’s Rust-based one, with the goal of building in a handful of different features. The dev is looking at using this compatibility to migrate their instance over to the new platform, while allowing the community to use their apps of choice.
The ones on the Sublinks roadmap are interesting, for instance the warning system: https://github.com/orgs/sublinks/projects/1/views/7
There was also this list from a few months ago: https://discuss.online/post/12787?scrollToComments=true
True a warning system makes sense.