DLP response time is insanely fast (~2 µs) because they're basically using PWM to modulate the brightness, but instead of each pixel getting a specific pulse width they're essentially sending bit-planes where the per-bit-plane on-time corresponds to the bit-plane's weight.

Sample and hold makes motion clarity worse. You only help motion clarity two ways: shorter frame duty cycle and higher frame rate.

Absolutely, the bit-plane modulation implies that the duty cycle more or less corresponds to brightness, so you only get close to 100 % duty cycle from a DLP when the output is close to full brightness. Though there is some additional trickery here - at least the colorwheel DLPs actually modulate the light source in sync with the bits, so for an 8-bit output the LSB duration is not actually 1/127th the duration of the MSB. There could be more tricks - it's probably not necessary to actually have all the LSBs around every time you show the same frame, which leaves more time to reduce the duty cycle.