I don’t use Proxmox, but since it’s all libvirt anyway, I’ve frequently found someone doing something on it that helps me with my VMs.

For instance, my GPU passthrough Hackintosh VM is part based on some dude who made a tutorial for Proxmox that applies elsewhere.

From Proxmox themselves: https://www.proxmox.com/en/about/company-details/press-releases/proxmox-virtual-environment-9-0

I love the stability and uptime and I don't want to break anything in my homelab. When would upgrading from 8.4 to 9 make sense?