Yep, flushdns is pretty useful. Used to use it often back in the DSL days when the network information changed but the cache didn’t update for whatever and resetting the network connection didn’t do the trick. Pretty sure it was a Windows bug in XP at the time. Looks like they suggest trying the Pi Hole in the GitHub issue, which has come up before but is lost due to the broken search function 🙁 But, yeah, splitting the blocking out to a different device may help take the load off the system. 🙂
Still haven’t gotten around to experimenting with a Pi. I really should one day. Always been curious about the Pis