I have been using Ox Yoke pre lubed cushion wads on all my sporting rifles for years and wouldn't load them without, especially when shooting heavier loads.
I guess Chuck/PA is punching a hole in them to act as an air bleed? Might or might not be necessary. I have never had a problem with air build up as long as the hammer was on half cock and no spent cap was on the nipple. With a flinter, that would not really seem to be an issue.
I find the cushion wads wipe the bore when loading, create a better seal when the rifle goes off, keeps the patch from burning up, and lastly increases somewhat the velocity, sometimes up to 50 fps, if I recall correctly. Been a while since I chronographed the guns.
Also, I don't cut them in half, I load the entire wad. It doesn't seem to want to tip that way. And I load the PRB and the wad as a unit. Maybe that is why Chuck wants to punch a hole, to allow compressed air to escape through the wad when pushing the PRB down the bore.
As always, YMMV