Does it work also with comments continuations? Would this approach allow having both nested replies (for Peertube, I think) and replies continuations (when not all replies are loaded at once)?

Does it work also with comments continuations

Yes! Nothing should break it, although I will check it manually. I would have to check this once again as I have not check if there's a different JSON structure for these continuations. Edit: Fixed

Would this approach allow having both nested replies

Yes, each comment would have an option replies Page. In YouTube there's only one level, so it would be null there.

To get reply Comments, you just call getMoreItems with the replies Page.

replies continuations

This would be a regular continuation / getNextPage(), nothing should change.

@FireMasterK ok, then this approach is good. Thank you :-)

Just one small issue - this implementation doesn't support multi-level threads in one page request, but I think that can be done later. (I'm not sure if any services do this either)
Edit: This is the case in Peertube

Is this PR ready to be reviewed and merged soon?

This will be merged after release 0.20.10 is released

Do we need to squash the commits?

I don't think that's needed