Likely not, yet, but one could be compiled for it, like Roaring Penguin RP-PPOE. I'm not sure how you could get it to work with wifi though. Typically PPPOE Linux clients are used on wired ethernet connections, so the N8x0 setup would likely require a fair bit of Linux work under the GUI covers. (As far as I know.)

I would focus on configuring that ISP device with PPPOE credentials, or replacing it with one that can.

Another possibility is to introduce a new device behind it that translates from PPP/Ethernet to wifi and normal ethernet. If it has a wired port for connecting a PC/laptop that would expect to run the PPPOE client, add a PPPOE wifi router there and connect your wired and wireless devices to it.