You could pre-generate the configs and certificates and then distribute them.
Or you could use one device as an introducer, and pre-populate devices with just the correct folders and a connection to the introducer. You’d then approve devices on the introducer.
Depending on what you’re going to sync it might not matter, but the most efficient topology here is probably not that all devices talk to each other. Each device connection has a memory and cpu cost, so you’ll probably be better off building some sort of tree or hub-and-spoke setup between devices.
I cannot set up a hub-and-spoke, tree or star topology. That’s the whole reason I want to use p2p with syncthing. From those 250 Devices not more then (max) 3 are at the same local network (VPN not considered)…
There are many subsidiaries and each one has a normal dsl connection (router with nat).
Than the HQ has a 10M upstream connection (also with nat, but manual port forwarding is possible).
And now I need to copy files to thous devices. It’s a shame that nobody thought about that when they were deployed initially… But now those colleagues are gone and I have to deal with this situation.
The physical location of the devices doesn’t have to determine the topology you use to connect them.
I would make a local mesh, if you have 3 devices in 1 location they are all connected to each other, then each one connects to up to 10 other locations with no location shared by the other local devices.