Must admit i'm not to familiar with the ABC control system. I gather it was fly-by-wire though - presumably had a lot of stuff that would end up on Comanche (Wonder what's next now that proj is canned).
I can see actively trying to control tip and root introducing a lot of (at this stage) unecessary modes of failure, not to mention development costs. For a start you have to design blade for structural integrity, flutter resistance AND you need a method to actuate the tip (beit electric servo or torque tube). You then need (say) to package the twin swash plates or servos, and control system. The system itself will definately need some level of computation to figure out required twist, since the objective is to reduce pilot workload - especially in autorotation where the biggest twist benefit is found. When fitted to intermesher you double up on all this!
It just strikes me that a purely structural and aerodynamic method, like powerful tip tabs and torsional compliance, gets you everything you want without added complexity. The control system would be conventional, accept that the tips sort themselves out for minimum induced drag. The retreating blade feathering would best be accomplished by connection to collective only, requiring correction for speed/climb
The downsides i can see are tip speed and control forces. Clearly the RRPM must always remain high enough for positive airflow over tip, setting a maximum theoretical u = 0.5. I don't really see how an intermesher could stop rotation anyway, since rotors are always assymetrical to avoid clash. Control forces would require a VERY torsionally soft blade, which would need some damping to avoid eigenmodes (clearly mass distribution for flutter avoidance is a given).
Perhaps think of this as a halfway design towards full IRAT, in the same way that the CVT+HS is a a step towards rigid. Full blown IRAT would be capable of u>0.5, but becomes more complex. You need the twin swash plates and a blade layup that causes tip to flex in opposition to blade bend for the forward quadrant, where aero-divergence could be a big problem. Again better to do this in steps - a ground test rig ideally providing hard data for each stage of development...
"Time to get back to a real job"
Yeah, i'm becoming an obsessive-compulsive forum surfer...
Mart