Can't say. Personally, I'm running vanilla Ubuntu LTS and rolling my own ZFS, NFS, containers, desktop and so on but "I know what I'm doing." I hardly see a reason to do TrueNAS outside of UI. With that said I would highly recommend to ensure your data sits on ZFS because it protects it from silent data corruption. If I had to choose between Proxmox and TrueNAS and one ensured my data is on ZFS, I'd choose that solution, and then think about other use cases.