Speaking as a sometimes TO...
I could see it taking that long, because when you're down to two ships, where each one ends up at really matters a great deal.
To me deciding if someone is stalling or not is going to require more than just how long. Taking 5 minutes to set 2 dials isn't unreasonable in all situations, but in some it could be 4m 45s too long...
You really have to consider a number of factors. Is the person winning or losing? What's the margin right now? How much time is left? Is MoV going to be a factor on where they place over all? Is the next move fairly obvious or not?
I mean if I got a VT or YT in a corner pointing to the center of the board, the number of moves I can reasonably make is limited, but if I'm in a E-Wing in the center of the rock garden and have targets on both sides then that's different.