Pretty much yeah, but as compact as possible.
Ideally of course, one could just plug a pre-configured handset into any network socket and it would work like it was in the office, but that’s not happening because of firewalls and most sockets don’t supply power.
So, a small box that sits in between the phone and the network, and one power supply, is the goal.
A small router like the Mikrotik device would do it, but it provides only passive PoE and I can’t see the working with a class 3 device. Easy fix would be to combine the mini router with a mini poe switch and duct tape them together, but that needs two power sockets and loses out on the ‘elegant solution’ measurement!
Mikrotik actually say they may make a proper 802.3af device in the future, but don’t have one right now.