Been using tinc for god knows how long... Perhaps 20 years? It's been fantastic. I really don't know why people are wax-lyrical about wireguard. tinc was doing it 20 years ago. UDP? yeah. encryption, mesh, proxy ARP you name it. I've had countless install and it's been the best VPN.
You even get a 'dot' graph of your current network status if you want to. When 'git' was invented, I put my /etc/tinc/*/ into git with the public keys, and installing a new host to the mesh is one 'git clone' away.
Most underrated open source software ever.
I will say however that development appears to have fizzled out. I was really looking forward to some of the changes in 1.1, but it's been in pre-release for years now and doesn't seem like it's closer to being officially released.
I've largely replaced tinc with Nebula [0], but I still think fondly of it.