Oh yeah, I 100% agree with that, honestly two VPNs are better given you wouldn't want your normal VPN to terminate into your management vlan (nor should you want your management vlan to have access to the internet). I thought we were just discussing normal homelab stuff, all administrative stuff should really be oob.

USB's are another really big no-no where I work, and running a different OS on my work network would 100% throw a lot of flags in our SOC as it's essentially plugging a rogue device into the network. In my understanding, a reverse proxy allows access to specific resources, if configured properly it only allows access to your DMZ.

VPNs allow you to become part of a virtual network (like one you aren't physically connected to), frequently providing access as though you are directly connected to the whole network. I could set up a VPN to my DMZ I suppose, but that just feels weird as hell as the whole point of a DMZ is to be an area you allow the public internet to reach (sometimes requiring authenticating to the reverse proxy).