When testing quick simple application, full hardware virtualization is often overkill. I heavily rely on Proxmox VE, but spinning up unprivileged Linux Containers (LXC) is where you get real problem. You have to nail down the UID/GID mapping early, especially if you are bind-mounting external storage or else you will face endless permission errors. I am still getting a hang of thie uid/gid mapping. Will add more once I have more confidence on it.