Id recommend the following
If your under attack you can't us a transit zone @ level 40, lower levels can depending.
If a player with-in 10 levels of you is close by a transit zone you can't use it.
A lvl 40 from the other guild can guard lowbes this way vs other 40s , if you want in you have to get threw buddy in full pvp zones only.
If your a lowbe and a level 40 is chasing you or guarding a transit zone a level 29 you can use it in regards to proximity blocking.
long story short lowbes aren't affected the same way unless their close to the same level as one another so they can run for the hills when needed from lvl 40 players, not vs same level players and high level players are 100% affected by the transit zone blocking.
This only applys to full pvp zones. no pvp zones are not affected.