said by bishun:
What I really intend to do, is assign at least 3 of the IPs to WAN interface on separate routers, for a lab setup; the goal is not to have to chain any of them behind each other
If your isp allows you to have multiple pppoe sessions, then each router can initiate it's own pppoe session.
If your isp only allows you to have one pppoe session, then
must initiate pppoe session
The public ip's can be configured manualy on each router or if the modem supports using dhcp for the public ip block dhcp can be used to allocate the public ip's.