If you should decide to return the Eeros then I’d suggest considering the Linksys Velop range.
These do support PPPoe and I’ve had good experience running them against a BT DSL connection (in my case using a Draytek Vigor 130 modem).
I bought these a couple of years ago because at the time they were the only Eero equivalent available in the UK that supported Ethernet backhaul between base stations (which can offer significant speed improvements for devices connected to satellite stations).