I would like to suggest 2 new resource pack features that Minecraft added recently:

1) The ability to send multiple resource packs
(I wasn't able to test if the current API allows this, because when I tested sending resource packs, they just aren't applying. They download, and the red screen comes up, but nothing after that ... I'm not sure if this is a bug or an issue with my packs)
Currently the method is Player#setResourcePack, so I wasn't sure if that allows "setting" more than 1 pack.

2) The ability to remove packs from the client

As per McWiki for 1.20.3-Pre-Release-1
""
General
Some additional options are added for 3rd-party servers software:

• Client can now accept multiple server resource packs.
• New packet was added to un-apply server resource packs.
  ""

Thank you for your considering