I don't think it is a plug-in, but rather built-in (hard-coded). I might be wrong there, but I don't see any files pertaining to it so it's most likely entirely server-side.
TLAGSNet configuration is in /EXE/flhook_plugins/playercntl.cfg
The relevant part starts from line 16909.
The actual program logic is probably in playercntl.dll, in the same directory.
GRP TLAGSNet users see the activity of pretty much every gate/lane that is not included in another TLAGSNet zone.
That includes the Taus, Omegas, Sigmas as well as the independent systems around Liberty, and even the Nomad gates/lanes in the Omicrons.
It can get pretty spammy.