I decided to go with the "round underneath at the bottom of the trunk" option, for easy bucking.
I first tried cutting part way through the prop branch, thinking that pulling with the log tongs would cause a strip to peel off the back of the prop as I pulled it away with the quad.
What I didn't factor in was that the prop branch got jammed into the ground by the falling trunk, at least a couple feet deep; No way I was pulling that thing very far at all with the quad. 😯
Pushing on the trunk from both sides with my hands, it seemed like the trunk was wanting to go downhill, plus the prop was holding the weight that way, so with two plastic wedges holding the kerf open I slowly continued to cut the prop from the uphill side, standing as far away as I could and beyond the end of the trunk as much as possible. When the amount of wood left to cut was getting pretty small, the trunk moves slightly on the prop, in the downhill direction I thought it might. Then I got back on the quad, pulling downhill, and was able to break the remaining wood and pull the prop branch out from under the trunk, which then sat down on the round under the root-ball end.
Whew, another scary job done, and i lived to tell about it! 😅 🤗 My nephew came over the next day and we lifted the prop branch out of the hole.
Before I cut the prop branch, I trimmed the previously cut rounds of punked sapwood and hauled them to my nephew/folks' stacking area. I tried to whack a couple with a maul, but quickly decided that it was a fool's errand. 👇 Once again I got to wondering "How the heck did they do all this by hand back in the day??" 😖 I guess they burned a lot more easy-splitting White Ash and Red Oak than they did Sycamore, Gum and White Oak. 😏