We could implement re-ordering based on domain rules locally, yes.
It really depends on how many people are interested in that and the feasibility of it.
As you mention, it would probably require fetching more results to make it worth while in some cases, since we don't have as much control over it this way so we can't optimize how we do it like we do server-side for those types of things.
We do have a proof of concept implementation of the local settings already, but it does store it in local storage and not within the extension itself.
We would need to see how difficult it is to put it into the extension but I think that is something we can definitely explore.
