Virtual library and opds feed

I’m on calibre 4.18 and use it for storing comics and ebooks. Comics are tagged with ‘comic’ along with suitable genre tags, and I have two virtual libraries - one showing just the comics, the other not.

I’ve just picked up chunky reader, which can pull comics from calibre server using opds, but I’m finding the feed a little limited.

I can go in tags and select the ‘comic’ tag to see just my comics, but that shows them all. I’d ideally like to be able to select my comic virtual library so I can then further filter the list by selecting a genre tag or series.

I appreciate this isn’t currently possible per this thread, but wonder if that’s a limit in the opds standard or just the implementation in calibre server?

If the latter, might this be considered for an enhancement?