Searched back and found a thread that described being able to stop sonar ie 2D, but keep LVS running. After adding the GT-54 to the TM and trying it out today, it seems if I pause 2d, then the LVS also pauses. If I un-pause LVS, 2D also un-pauses. I am running a split screen, but also tried it on individual screens, but the same issue occurs. So not sure if I am just doing it wrong, or if recent updates have changed something, or... I'm running an 126sv (not gen2) and LVS-34.
I guess the same question for DI/SI - I didn't even look at those, but I will next time out :)