Re: Cool points for the developers
Once you have a ... murder, shoal, ... mob ...??? ... of feisty PI's around the house, then you gotta manage them. Hopefully with something like Puppet or CFEngine. That tool will need a server.
Probably one also needs an apt-cache, like apt-cacher-ng. Which, for simplicity, is Another server.
Those would fit neatly into a PI-4, especially when virtualised. In my experience, management tools tend to be quirky and some of them (CFEngine?) are even installed from a shell-script rather than a package, creating "a mess" from the start on a packetized system. This way we can keep the mess in a container.