Right, I was referring to my parent comment that talked about pulling Docker images which come from the internet unless you set up a proxy.

Ok, that depends on the docker images; things like pihole are relatively small (300 MB, including all layers); I would be more afraid of running containers over NFS slowed down by rpi ethernet, than downloading the images themselves.

Agreed. I'd have it set up so that there is some local storage via a USB3 thumb drive to hold the container images, which anecdotally pretty easily hits 80MB/s for reads, often hovering in the 100-110MB/s range.