@ezr-design
IIRC the strategy to deal with lost steps is to compensate during the next move.
IMHO the purpose of closed loop steppers is not to increase accuracy within microstepping range, but handle lost steps and layer shifts.
I wouldn't be surprised if the 1HCL cuts off two least significant bits to reduce AD-conversion noise. So the real resolution would be 4096/turn. Not much more then the regular 3200 microsteps/turn @ 1/16.