Hi
Can you use either PPPoE or DHCP, i'd perfer PPPoE over DHCP but that depends on setup to setup.
In your case, you require a Dynamic-profile in which the logical interface creation would automated using demux0 or can also use IFD and configure predefined-variable-defaults within the dynamic-profile that pull policer-filter to be applied on the client (or just call policer/filter with dynamic profile if same filter is to be used). Call the dynamic-profile under interface with auto-configure. This way, you dont require configuring static units/vlan.
Do you want to deploy DHCP-LS or PPPoE? Choose one and i'll build you a sample config!