SOLVED: Proxmox LXC Hardware Transcoding

[C0nfigurator]

So I got it working by forwarding the GPU like this:
dev0: /dev/dri/card0,gid=44
dev1: /dev/dri/renderD128,gid=993
instead of
lxc.mount.entry: /dev/dri/renderD128 dev/dri/renderD128 none bind,optional,create=file
in the LXC config.

Thanks a lot for the help up to this point.