Seems like overkill. Why not just use openwrt and the adblock package? Grab a tl-wr841 for <$20 on ebay - some go for $5 You could even get an orange pi or Rp

Seems like overkill. Why not just use openwrt and the adblock package? Grab a tl-wr841 for <$20 on ebay - some go for $5 You could even get an orange pi or Rpi zero + ethernet to usb adapter and hang it off your existing router for power.