The zimaboard runs pfsense & an nginx reverse proxy, then all six of the mini-pcs run proxmox. 4 mini-pcs run k8s clusters (talos) and the other two run home services and selected one-offs (home-assistant, plex, bookstack, build-tools, gitea, origin servers for a subset of projects).
It was a lot easier to set up than I had expected. Its was still a massive PITA though. I got what I wanted out of it work-wise, and its a nice little novelty.
I've been thinking about ditching most of it for a while; I like the idea in the article about breaking it up - move one under the TV, one into the office, one under the stairs, and the remaining 3 + zimaboard I'm tempted to sell. I'd keep running proxmox on them, but I wouldn't link them up. The key thing that needs to happen for this to make sense is using something like cloudflare to route domains.
The part I never sorted properly was storage. It has 3TB of storage, but getting that storage into k8s for proper dynamic allocation without giving random nodes CPU perf issues was a too-long-for-one-session task which meant it never got finished. I was tempted to add a NAS, but most NAS's are horrid.