With a variable scope, I sight in at the highest power becauseaiming iseasier. BUT, once zeroed, I fire three rounds with the scope set at the power I use most when hunting-4X-just to ensure that changing power does not change POI.....

I do all my load workups at the highest power. Once I've settled on that, I ALWAYS shoot again at the power I'm Going to hunt with, usually 6X, to check POI. I learned the hard way, many years ago, with a scope that changed POI with magnification change. I hadn't realized it until I missed a nice buck and checked the gun out. Right on @ 12X, 6'' high at 6X. Most of today's scopes seem to have corrected that problem, but I never take a chance anymore.