2013 Escalade with a collapsed lifter. Rocker cover removed and #4 intake rocker arm clearance is excessive (similar to your videos). Used the release tool with as many hits as I dared and even an air tool for rapid hits, but NO push rod flying out.
I was about to give up when I noticed the push rod was now obviously sitting 1/2" or so higher than before. So I reinstall the rocker arm and sure enough the tappet clearance is now zero. It appears the lifter released, just not spectacularly.
Rotated the engine manually through several cycles and the push rod/rocker valve are moving through the normal cycle. It appears the problem is fixed, but I am really hesitant to reassemble everything out of fear this is fool's gold.
Of course, I worry that as soon as power is applied, (even with the VLOM delete) the lifter will collapse under its own "push".
Is there a way, to manually check that push rod to confirm the lifter is actually released and has locked itself in place?