Forward certain apple.com sub domains (specifically iOS updates) to a local squid instance?

I was looking at a couple things that could help speed up my local network and I came across Squid and was wondering if it'd be possible to make pi-hole forward only certain domains to Squid?

I have found here that there aren't but just a couple URL's that actually need to be forwarded. Basically I'm try to setup something similar to an Apple Caching Server on my rpi3b like this person did here.

Also found instructions on how to setup Suqid on a rpi3b here.

Please elaborate. How would the Squid proxy be arranged relative to Pi-Hole? As an upstream server?

Maybe I'm missing understanding how Squid works exactly?

I was thinking it'd be after Pi-hole.

Computer --> Pi-hole(&unbound) --> Squid --> Router --> Modem

Such that only dns traffic would go thru squid. And then maybe I could setup Squid to only intercept the 3-4 Apple domains and it wouldn't slow my network down drastically.

So come to find out I had the order wrong. Should’ve been

Computer --> Squid --> Pi-hole(&unbound) --> Router --> Modem

Squid can be setup to only cache certain domains. So in the coming days/weeks I’ll see what I can get going

For reference