In general I've had good experiences when riding through construction zones and have found the flaggers and others to be friendly and considerate. But there was one counter example. Two of us were riding together and were first in line when the flagger indicated our direction should stop. He then told us that we should wait for the whole row of cars on our side to go through before joining them at the end of the line. My response was that we'd agree *if* he made sure that the other direction of traffic wouldn't be allowed to start until we were through the one-lane zone. He assured us he'd do that and we waited as instructed when it was time for our direction of traffic to go.
Needless to say a gap formed between us and the last car going in our direction and as soon as that car reached the end of the const. zone the flagger at that end let the other direction of traffic proceed - straight at us and we were forced to jump out of the way with our heavily loaded touring bikes.
So if you're instructing the flaggers be sure they remember to instruct the one at the other end if there are bicyclists coming through and to wait for the last cyclist, not just the last car/truck before allowing traffic to proceed through a zone too narrow for sharing.