I used everything from the palm of my hand if I was just slipping one in to stop a set back to a 5lb council that our local blacksmith custom polled for me.
I always tried to avoid having to really wail on the wedges. When you hear somebody knocking wedges for more than ten minutes it's usually a sign that they screwed up. They read the tree wrong or they're trying to pull the tree around with wedges instead of tapering the hinge, throwing a chunk in the face, or putting in a sizwheel.
You'll notice the older fallers spend more time on useful cuts than they do beating on stalled out wedges.
I don't know if it makes wedging harder, cause you at least have gravity helping you swing, it does make wedging a lot more dangerous, cause it creates a fulcrum that can shear off the hold wood.Typically, the deeper the face the harder the wedge driving due to less leverage. Too deep and the load will increase, inviting disaster.
Today tree had almost all of its limb load on the back side. The tree posted earlier was a back leaner. Due to hazards both had to be felled against the load.
My back cut today also wasn’t level. My error. I am told a sloppy downward sloping back cut also makes wedging harder.
Not sure which scenario you are addressing - the deep face or the sloping back cut. As you know, gravity doesn’t help you on a face cut unless you are cutting compression wood or you have converted the back cut compression wood to tension wood, or severed it and supported it; both of which require some mechanical means - wedge, tension line, jack, heavy equipment, etc. If your compression wood is in the back you have to move the center of gravity forward - a deep face gives you less leverage with a wedge thus making it harder to drive - like starting in second gear. Also like 2nd gear, the stem will be lifted higher with each movement of the wedge. So theoretically, a deeper face requires less wedge height to get the job done but requires more force to get it there - and as you noted it makes things more dangerous - bust the hinge when the center of gravity is still in the wrong place and it over. Nothing here you don’t already know, but maybe some don’t.I don't know if it makes wedging harder, cause you at least have gravity helping you swing, it does make wedging a lot more dangerous, cause it creates a fulcrum that can shear off the hold wood.