KJ, you're dead right about exercising your heavy leather to supple. IMHO, just doesn't work right otherwise. I use whatever is handy, Neet's foot, Mink oil, Bulla Bulla Butter, etc. then twist, turn, & exercise the startch out of it! Above combo 75% beeswax & oil sounds interesting.
Different body shapes require different fits. Just so you can get to your arrows easily enough. Your retrieve technique may change to suit also. No one specific way imo. Try sliding the quiver under your arm for tight spaces in the woods.