Thank you! This is something I’d been holding out for a while now waiting to see if it’d be implemented in the Lemmy API. I finally decided to roll my own solution in the meantime.
There are a couple of issues with sorting, for instance Scaled and New Comments sort modes are not accurate in multi-communities. This is due to limitations in the API where I don’t have access to the necessary information to accurately implement the sorting algorithms client side. However, the pages are still fetched from the API using the proper sort mode, so all the same posts will be present in the per-page feed, the sorting just won’t be quite as accurate.
Other than that, I am not aware of any other issues. Though this is new and I only tested it for a few hours before releasing the update. I do think I will add an option to the editor so that multi-communities can be linked to accounts. This will allow setting multi-communities for a single, or multiple accounts. I may do the same for favorite communities as well.