I find the paddle on the Serpa holster is to large for proper cross draw.
I prefer cross draw for all the reasons the Good Captain has listed.
I do practice positioning my body so that the gun needs not sweep as i take up a Chapman stance.
I am also of the opinion that practice never needs to be done with live ammo for many of these outside the box techniques.
It wasn't that long ago where a man lost his life doing a one hand cross draw technique that should never have been done ever loaded in practice.