An Intersection remote (akin to a Union remote) would be nice. For example, you could then define:
and use this to easily create, say:
Videos: = alias
So you can easily back up your big huge videos to all of your cloud services that (A) can handle it and (B) won't charge you an arm and a leg if you do so, using only a single
rclone copy . Videos:.
Note that the intersection of two remotes could be nothing, in which case the Intersection remote could be no-op.