Splitting predicates into multiple groups

A given predicate always belongs to same group, i.e will always go same node (and its replicas)
So this node/server will eventually fill-up and there is no way to horizontally scale the storage.

Has any work been done on splitting the predicate into multiple groups? ( https://docs.dgraph.io/design-concepts/#group)

If not, what solutions are offered, without vertically scaling (which has limits and be expensive) ?