I haven't abandoned Proxmox yet, but the take here resonates with me. I do not like configuring appliances. I prefer defining infra as code, having that diffable, assertable, etc. I have had pretty good luck managing Proxmox clusters with the Proxmox API (https://pve.proxmox.com/pve-docs/api-viewer/index.html) or just letting the agent shell in as root (lol). I built a very simple provisioning tool called vmfactory that takes some really somple config on disk, bakes a fresh qcow image, pushes it to proxmox and then configures networking and boots it. It's extremely rudimentary but has been working well for me.

I did abandon TrueNAS, however. It really is a locked-down appliance. Good luck installing custom software on the base OS. I have a domain-joined Ubuntu/ZFS box that inherits a lot of policy from FreeIPA and/or Ansible config that is all backed by files on disk. It's been really easy to orchestrate what many would consider overkill in my homelab because literally everything is represented in a single Github repo.

I yanked vmfactory out and into a standalone repo if anyone is interested: https://github.com/whalesalad/vmfactory

https://github.com/Telmate/terraform-provider-proxmox ...

I run Ansible against Proxmox hosts to ensure the config on them is what I want, and then Terraform all VMs into place on them. It's not too far off from having your own mini-EC2, minus some of the nice trappings like load balancers.