Alas, not all taps are created equal (depends on the filter). I'm not sure what the details of the closed-form-16M are in HQP, but what I'd really like to hear is idealized sinc interpolation filter (
https://en.wikipedia.org/wiki/Whittaker–Shannon_interpolation_formula) at 1M. 2M. 4M. 8M. 16M. etc. At some point, we'll no longer hear any difference (at least with the current WTA2 and noise shaper), and we'll have arrived.
Taking a step back, I try to keep the DAVE block diagram taped to my laptop screen when I'm trying to grok these things. mScaler is basically taking the WTA1 filter ("Home of the Taps") and putting it in an external box. It applies the 1M taps and injects 16fs signal via dual coax into the rest of the pipeline basically bypassing the built in WTA1 filter in the DAC. Hugo2, TT2, etc. all have similar pipelines.
Taps are a fantastic way to simplify "What makes this special?" to a number that all of us can grab on to (1M is better than 140k!). However, a HUGE amount of the Chord magic is in the WTA2 and noise shaping digital stages, and in the actual DAC itself (in the case of DAVE the 20 element pulse array and output stage). Taps are critical to have the best input to the pipeline as possible, but I've come to believe that the real magic happens after WTA1 (post taps), with DAVE being the Grand Wizard of magicians.