I tried (unintentionally) this DAC/AMP with a Susvara. Didn’t spot any special magic about it or any major difference, compared to e.g. a Hifiman’s EF1000 DAC.
Was also playing with “soundstage enhancement” functions of the very hyped Audma Maestro HPA1 driving a Raal Immanis. All it could do for me is to make the vocals sound closer than by default (I can achieve a similar effect with just a single peak EQ filter, btw). The sound stage switch on the Zähl H1/HM1 also has a super subtle effect to my hearing. So, I guess I’m not susceptible to the “stage enhancement” effects in general.