I'm a bit of a paranoid freak that likes lists, so I've got a PiHole that has a total list of 14-16M blocked domains.

Great idea, and good for casual blocking, but I'm almost moving to an "allow list" mindset. This solution would probably work better for that, I wonder if the good parts of the internet would fit into an 140k list.

Do you host your lists somewhere you can share?

Tbh, for the ESP32-C3’s perf, an allow list would likely save RAM and CPU time.