What I'm concerned about is that we so often end up trying to set the aircraft up while these guys are still working. I feel that we should stay out the way until they're done... and then go in to the flight-deck, and get things sorted out. As for the delay... put it down to "Aircraft Snag"... Not necessarily "Technical" (as in... who is to blame for the delay). My point here is that we should take the schedule seriously, but not as seriously as safety.
If the aircraft isn't ready, stay out. The schedule be damned.
I was working on a light turboprop several years ago when a crewmember felt it necessary to enter the cockpit and begin doing something. My work required entry from a panel directly in front of the left propeller, and imagine my surprise when I heard the power starter and saw the prop begin to turn. I was fortunate...and so was the idiot who climbed into the cockpit while I was working. I could have been killed, and failing that, so could he, when I got hold of him.
If maintenance still has things to do when you're in the cockpit, perhaps it's a little early for you to be there.
With personnel working on the aircraft, people having access to electrical controls, pneumatic controls, hydraulic controls, flight controls, etc...is a dangerous thing. Especially if they're not working closely with the maintenance personnel, and in constant communication.