Thanks for good info.
Bad news. I emailed Precision Camera Works and the new heads with AS clamps are made so the clamps cannot be removed. They add something besides just doing a simple reversible Loctite job on the screw - it seems likely that they have some sort of peg/slot system as for the RRS clamps. That's good if you like the clamp and don't plan to change it, not so good otherwise. But I would consult Precision Camera Works (sells and repairs AS gear), Rod Klukas the distributor, or Arca-Swiss.de to see if the clamp can be changed by factory authorized service. For the D4 or Cube, I'd say it would be worth a high repair bill. For the more common models Z1 and P0, swapping, buying used, or buying new may be cheaper if you can sell the old head.
I actually like the flip-lock lever, it has grown on me, and it is reassuringly solid and safe, but I have noticed that the Sunwayfoto 100 mm nodal rail and the Kirk L brackets can't be accommodated at the same setting. I just won't touch the setting when in the field, due to having had the clamp fall apart the first time I attempted to change the factory width setting. Chasing tiny washers is fine on a clean floor, but I have no desire to sort through 4 inches of leaf litter.
If anyone knows of a different 100 mm nodal rail with perpendicular clamp at the end, I would like to hear about it, because the DP2 Merrill needs a short nodal rail so the other end of the slide doesn't show in the photo. I suppose the other thing I could do is buy one of those small back-to-back clamps and place it on the regular 150mm nodal rail.