Hi @mpomerantz , I took a quick look at Plume. It seems to me it is a form of Internet over power lines or EoP. While this is better than wifi, I don't think it is as good as quality ethernet cables running from your router directly. I believe power lines can impart noise to the ethernet signal.
I do use EoP (Eero Pro mesh with base station and extenders plugged into power receptacles) in a vacation home with no ethernet wiring.. This is easily better than wifi, and a quality ethernet cable or filter (NA Muon Pro Ethernet filter) improves things further.