Detect the target table is easy, but it seems tricky to redirect the flow to pg build-in logical replication (not necessary to re-implement it, especially it was written in C language, so redirection is the right way).
In fact, you could use pg logical replication directly for some cases like big and real-time data flows. But currently, it has one big flaw: bi-directional replication or multi-master replication is impossible, where it would cause dead cycle loops, because it do not filter any origin currently, you could check function pgoutput_origin_filter.
And, even if the filter is right, it still lacks of conflict solution, but pgcat could help there, and you don't need to use pgcat, because pgcat has trigger way to resolve conflict, you could check pgcat_setup_lww command.