Idk, but saddle to sternum contact going *up* just shouldn't happen. Seems like to you're way too compressed. Ledges are power (and finesse) and most of us need more, not less, leg extension to generate power and increase maneuverability (of our bodies, not nec the bike). Color me contrarian, but I think the saddle is only an *obstacle* going down or in the air; otherwise it's a critical fulcrum that focuses your riding position and enables leverage.
I'll offer that bunny hops are not a good model for ledges, imo. You need more run-up distance and more time to provide for compressing/rebounding your suspension, which makes the coordination of the complete move trickier. I think there are also too many limits to that approach - tall ledges, consecutive ledges, dips before ledges, etc - where the technique isn't just harder, it's counterproductive. I also find that compressing shifts my weight forward precisely when I need it backwards.
Using your torso as a lever to raise your front wheel can be quicker, more predictable, and more forgiving than compressing. More forgiving because bad timing on the compression can lead to an endo (up!), for instance, whereas if you lever your font wheel up but not enough, you can still roll it because your weight isn't working against you.