The recent move to the converter driven setups (like the Lencodrive & Bruno/Lenco) over the time tested clutch/Lenco setup in P/M probably never would have happened without the recent mentioned stator design advances allowing the converters to consistantly handle the 2500+ HP numbers. But the birth of the ADRL circuit also played a big part because of their "outllaw/anything goes" way of thinking when it comes to the P/M rules. They split the blown & nitrous cars into two different classes so there was no more juggling the rules to pacify the crying about fairness/leveling the playing field you see with the NHRA/IHRA P/M cars. And their "no minimum weight-no maximum cubic inch" thinking on rules meant that the P/M guys could once again experiment & try new (and old) ideas again instead of just building the same old "cookie-cutter" cars to fit the more restrittive NHRA/IHRA rules.
Without their hands tied on weight & cubic inch numbers, there was once again experimentaion with engine height/fore-aft placement, trans setups, and electronics. At first most didnt mind admitting to using a delay box.......but the use of the real-time traction control boxes (like the Davis unit) was kept a secret by a lot of teams at first, even though the rules permited them. But now that everyone is pretty much used to the idea of a computer controlled traction device, they don't mind admitting to using them in classes that allow them like the ADRL/outlaw P/M & 10.5" tire cars.
At a recent local TOPMA P/M show in Kennedale TX there was a converter in probably 85% of the Pro Mod cars. One of the remaining clutch holdouts at that show was a blown sbc vette. They said they had tried the Lencodrive earlier, but it didn't work for them (at this time) and switched back to a clutch for now.
And because of the no minimum weight rule, a lot of the P/M guys were putting the cars drastic diets. Some guys have tried rear frame sections made out of Titanium instead of 'moly, Titanium firewalls instead of steel, standard rear end setups instead of full floater rears (that has changed though), CarbonFiber wheelie bars, new ultra-light weight CarbonFiber bodies insted of the normal Carbonfiber bodies, etc, etc, etc.
Heads-up drag racing will always evolve....if the rules let it.