This domain ichnaea.netflix.com.
it is by far my blocked domain, what does this do, and is it better if I enable it so it doesn't flood my pi-hole? 16k hits in a little over a day.
From bugcrowd:
ichnaea.netflix.com
Ichnaea is a logging endpoint used to collect client information.
If Netflix still works without issues I would leave it blocked.
It's trying to send logs (speed stats, connection stats, ad-tracking) back to Netflix. It's likely set to keep trying if it fails - and considering PiHole is blocking that traffic - it will continue to generate more failed attempts.