The only neck constriction I heard of is when people don't support the boa around their necks when they bend over to do something. So it is not feeding response that cause the reaction to coil around the neck, it is the fear of falling.
Of course, it's a different ball game when you deal with the giant pythons over 12-15 feet.
Of course, it's a different ball game when you deal with the giant pythons over 12-15 feet.

goodluck!