Split PPPoE users on two servers

Hi everybody,
i’ve a little question.

I have a CCR1036 that collects VPLS tunnels, and send pppoe requests via VLANs to two pppoe servers

It actually works fine.

I would like to set it in this way, one server for collecting pppoe-clients with private subnets, and the other server for pppoe-clients with public IPs.
I know that the best practice is to set the Service name in every customer CPEs, but since they are more than 2000, i would ask if there’s
something that i can do at Mikrotik’s stage