Agreed, custom aggregators for kbin and the fedverse in general, will become a thing.
I can see a view that combines the hot posts from each of my subbed communities, with the top 1 or two posts from each featuring, filtering over a time constraint or some other ranking system.
A client side implementation would be possible, but expensive in api calls. Server side should be easier. Maybe even defining a query language of sorts that can be user customised, if we wanted to be really fancy.
Some form of weighted rank, combining activity and interaction. I am subbed to some slow communities that are just starting. Maybe having a post or two in 24 hours where I would want those posts to rank highest. Subbed fast paced communities would then rank lower if we factor frequency and interaction on a per community basis.