Best place to utilize the jack

Right in front of, or partially on the spring hanger for the rear.

The frame horn is reinforced there and I agree about partially hooking or at least paying attention to the raised areas on the jack pad. It's easy to crease the laminated sheet metal our frames are made of.

It's always tough to get jack stands on an area with enough flat surface.
Most stands that are worth anything have a half round cutout that causes them to not sit well.

I made 1x stock pads with sheet metal skirts to make the surface perfectly flat.
Doubt seriously they will slip and if the split it's only 3/4 inch, but the weight is pretty evenly distributed.