The flaps should be set up so that in the deployed position the servo arms are is in a straight line with the pushrod or as close as you can get it. This will give you the least amount of amp draw and the greatest amount of power in the deployed position. In this position there is no air pressure load on the servo. What you dont want is a 90Deg angle between the servo arm and the push rod, This is the worst position to be in and the servo will draw stall current at this point. The flaps are the worst surface to have this problem with. Other surfaces will not react this way. This one item will bring more planes down if you do not have a bullet proof battery system. To recreate this deploy the flaps and push on them both and check the amp draw with a simulated air pressure. If your batterys will fail it will be in this test.

Another way to look at it is if your flap servo is in the up position 1-2 o'clock and in the deployed position around 9 o'clock the pushrod should extend out the 9 o'clock position to the control horn for a push to deploy or 10-11 o'clock retracted and 3 o'clock deployed the pushrod should still extend out to the 9 o'clock position in the pull to deploy