Hi John, thank you for sharing the great information. Very happy to hear that you've improved your speeds.
Did you switch your DNS to Cloudflare 1.1.1.1 (and 1.0.0.1) or Google 8.8.8.8 (and 8.8.4.4)? For other people who'd like to do this you can find it on the Connection Guide under "Step 6 - Improve Your DNS Resolution and Privacy".
DNS over HTTPS is available for Firefox users. I'm pretty certain that this is going to become the new standard and will eventually roll out to all browsers. May be able to do this at the router level in the future too. ISPs won't like that. Right now, all of your DNS traffic is being send with clear text, meaning it could be snooped. DNS over HTTPS encrypts your DNS queries. Encryption always has the potential to slow things down but actually (reading the link above) they say in many cases it's actually faster.
Again, happy to hear you've picked up some extra speed that you've been paying for.