I’ve dealt with exactly the same dilemma in my homelab. I used to have 3 clusters, because you'd always want to have an "infra" cluster which others can talk to (for monitoring, logs, docker registry, etc. workloads). In the end, I decided it's not worth it.
I separated on the public/private boundary and moved everything publicly facing to a separate cluster. It can only talk to my primary cluster via specific endpoints (via tailscale ingress), and I no longer do a multi-cluster mesh (I used to have istio for that, then cilium). This way, the public cluster doesn’t have to be too large capacity-wise, e.g. all the S3 api needs are served by garage from the private cluster, but the public cluster will reverse-proxy into it for specific needs.
Between homebrew and nix, the amount of foss macs can run out of the box is pretty close to some generic Ubuntu (nixpkgs is technically the largest repo out there, but not all of the nixpkgs are available on mac).