I'm totally with you on this idea Larry. MAD himself even proposed this idea to me initially, that the way our hands and sticks work, could be transferred to our feet. And ideally, the stick would hit a drum head at a 90 degree angle for the most natural rebound, likewise should the bassdrum beater hit the head at a 90 degree angle! By the way MAD, if you remember our conversation regarding not burying the beater, it's getting easier and easier
I do recall our discussion Sjogras, and while it's true that you can transfer some of the principle of your hands to your feet as far as emulating the movements, with your hands you do not hit a drum head on a snare or a tom at 90° angle, it's impossible, you'll hit the rim before you'll hit the head, you apply a small angle to the stick, at best you'll produce a rimshot, but the stick is still hitting at an angle.
The discussion on this thread made me check my beater, and it hits the head just a fraction after the 12:00 position, it's almost negligible, about a 1/4 of an inch, not something that would make a lot of difference if was hitting at the 12:00 position, I'd say it wouldn't make no difference whatsoever.
However, it is possible to hit the bass drum head at a 90° angle by fitting the Sonic hammer on the pedal.
Furthermore there's a lot you can do to make the current setting of your pedal, adjusting both the beater angle, the footboard angle and the spring tension can easily make your pedal more efficient without any expenses Larry, do not forget, simply fitting a lighter beater without changing your current setting will affect the feel and the response of the pedal as a whole, and you might not like the end results, it could affect the control and the accuracy of your strokes.
You've played with your current setting for years, perhaps just a bit of tweaking with the adjustments will achieve what your aiming for, if the ultimate goal is to feel less fatigue while playing with a smoother feel, your current pedal and beater is perfectly capable of achieving it, just a little patience and experiment and you'll be there, completely free of charge.
Right, now I'm done with the "trying to convince Larry" comments, lol, it's entirely up to you Uncle Larry
Cool to hear that your improving on the rebound technique Sjogras, keep it up