Set wireless interface using mac authentication

Hi

I have a customer who is using some RB with multiple wireless interfaces with the same SSID between them, and using access lists to define which client should connect to each interface (I didn’t even knew that was possible).
All the interfaces have default authenticate and forward unchecked, so that the acess lists doubles as an… access list, and forbids the connection of any other clients.

We’re currently thinking of changing the access lists of the RBs to a radius MAC authentication, so it’s easier to manage all the Aps, but I’m not sure if it’s possible to define in which interface the station should connect, since the authentication happens after the connection already happened.
Maybe some kind of reply the radius can send that mikrotik will understand, and maybe cache something.

I have been able to filter the interface the station can connect to, but it just leads to the station trying to connect until it randomly finds the correct interface, and that’s a very good solution.