At least Microchip isn't so insane that they are using network licenses for them.
Don't be so sure about that!
The XC compiler licence manager uses network or local licences. Unfortunately some versions have had the network given priority with the result that compilation can hang for about 30 seconds on every build while it is looking for the nonexistant LAN licence server. The current versions are OK, but I wouldn't be surprised to see that bug again in a future version.
It also 'phones home' for initial activation, which while understandable, is going to be a right P.I.T.A if you need to reinstall the toolchain to support a legacy product ten years down the line.
I fell foul of the unexplained compiler hanging a year or so ago, of course Microchip employees couldn't reproduce it because they're on network licenses, not Workstation node locked ones, so it took a non-Microchip person to realise that copying the license manager from an earlier version fixed the problem.
I've had more than my fair share of grief with Microchip compilers and licensing. I have all three of them. I lose about a day of productivity every year trying to fix licensing problems with my Workstation node locked versions because the licensing manager breaks. This can be for a number of reasons, but key to this is that on node locked licensing the installer picks the MAC address of a random NIC on your machine and phones home with that information. The hostname is also sent with the information but other than metadata I don't know if it's used in the licensing enforcement algorithm.
Each node locked license has three lives, and Microchip allow a single user to use the license on three different machines. Generous enough, I have it on my main desktop machine and a field laptop. However, if, during installation or upgrade, a different MAC address is chosen by the installer to the last time for whatever reason, it chews up another one of those lives.
So the moral of he story is to keep a record of the MAC address you compiler(s) are tied to and make sure during installation you use that one rather than let the installer pick one or you'll lose one of your lives.
There is also no way to revoke your old unused licenses yourself online, say if you move to a new machine with different MAC addresses, you must email Microchip and wait for a response back. A simple web page with your licensing details would be all that is needed, you pretty much have to register anyway as far as I can see.
One further point is to take care if you use their compilers in VMs, as these have their own way of managing MAC addresses.
The impact that broken licensing has for bone fide users is really not acceptable, when you can't rely on your toolchain to work due to a flakey and arbitrary licensing scheme bolted on top of it it really disenfranchises you. It's hardly surprising that there has been so much effort spent circumventing it as a result!