"Ports" seems to just be "tags" as channels/filters? The problems with all such schemes (channels or tags) when used for more than personal organisation, is discoverability by the other party. This is addressed by RelayBeam through the first party disseminating their per-port address. But this merely shifts the burden of organisation to the sending party when they have multiple relationships (and therefore multiple port addresses) with you. Now they must remember which address to use for what. This problem is multiplied as each person they interact with has their own set of port "schemes".

I admire the attempt to solve the communication organisation problem, but leaving aside any functional attempts to solve the problem (which I suspect will be readily solvable through 'message aggregator AIs'), the fact that this solution requires all users to use the same platform, makes this effectively DoA (excepting organisations that might mandate a move to such platform).