This is very unique approach.
you can define locations (set of switch and port).
Then you can create rule: if the mac is in group G100 and the location is L100 then apply vlan100. If the mac is in group G101 and location is L101 then apply vlan101. Otherwise reject.
with the approach above you can define the list of ports in management instead of in the CLI.
in advance: location groups can be synchronized by workflow from ERS switches...
other approach is to explain the customer that his approach is “not best practise and not optimal for troubleshooting (you need to check CLI and GUI”.
Regards
Zdeněk Pala