Not a great deal of progress tonight.
Flashed the newly received nanostation m2 and picostation m2 and investigated if any special configuration would be needed to support them as extender nodes. Surprisingly it looks like the answer is no, even though the nanostation m2 has a built-in switch.
Information about supporting these devices is logged here:
Started a build of latest sudowrt on
room.sudoroom.org: