Allow RSS following
I think this will be super useful. I suggest RSS to be treated as an account (that never performs any actions except posting), so that users can see how many followers it has, etc. So no or little effort would be required from the FE/client side. Friendica supports this. Also with services like https://rsshub.app/ (not affiliated in any way) literally any service can be followed (bird site, youtube, scientific journal, you name it).
I don't know how much effort this can take, but I would be willing to give 50$ if this is implemented in pleroma.