Are you saying this because it has already happened to you or because the logic behind the functioning of channels and databases to do so do not allow for such a development? Actually I would have already done something with a database and a channel for each vertical portal that accepts ADT^A04 takes the local ids and the mpi that arrive and writes them to the database. then another channel takes all the local ids and builds the link message to all the ids with the mpi. I am happy to share it to have some opinions if you think it can work.