Here again, a little disagreement . . . I just did the "thumb pressure" vs "driven in" test on one of my own .45 Dragoons. It nominally has a .0015" barrel cyl clearance (because of runout, it has a max .002" with a min .0015" in 6 positions measured). It is a designated cartridge gun. The trigger pull is 2 3/4 lbs (pos. engagement) and the hammer draw is 3.5 lbs (slightly heavy because it IS a possible S.D. weapon. Others are just under 3.lbs).
With the wedge pushed in (actually pounded in with the heel of my hand) the barrel /cyl clearance was a measured .0045" . I did this procedure twice with the same measurement. With the wedge driven in, the stated measurements above were observed (again the procedure was done twice). The wedge has been modified with the shortened spring mounted on the opposite end. This allows the wedge to be "captured" by the wedge screw. In other words, the shortened wedge spring pops up behind the head of the wedge screw so that it cannot work loose and obviously won't push itself in further. It's a modification I cal a "captured wedge". So, when the spring pops up behind the screw head as it is driven in, I know it is " home". Taking a measurement with a feeler gauge verifies the setting.
So, strictly in my opinion, I don't think you can fully seat a wedge with your thumb (unless you're the Hulk), driving the wedge in is the only way you will "marry" the two assemblies.
Mike