you can create your own bash file to launch your game in LAN mode, it's what I use on windows with a batch file
this is the full command for LAN Mode
start /wait /abovenormal bin\plutonium-bootstrapper-win32.exe t6mp "%gamepath%" -dedicated -lan +set key %key% +set fs_game %mod% +set net_port %port% +exec %cfg% +map_rotate
and make sure that your cfg is the latest one