I thought you are talking about this specific kind of integrated amps. Otherwise, please know that NAD has been "using class D before in an integrated amp", and quite a few have bench test results available too.
Just visit the NAD website and look under "Integrated amplifiers", in fact most of those listed are class D, and they correctly called them "Hybrid", as the conventional integrated amps are usually described as something like
"An integrated amplifier is simply a device that combines the preamplifier and power amplifier into a single component. ". NAD's Hybrid integrated typically include features such as build in DAC and streaming, even room correction such as Dirac Live.
Examples of some class D integrated/Hybrid NAD amps that have been measured:
D3020 - Hypex modules, released 2013 or earlier, measured by Stereophile
D3045 - Hypex modules, measured by HTHF, and also ASR
D7050 - Hypex modules, measured by ASR
M33 - Purifi amp modules, also a streamer, measured by Stereophile and ASR
C3050 - Hypex modules, Stereophile and SoundstageNetwork measured the LE version
I Googled for reviews and found the above models that have measurements available for you. The C 3050 was not measured, but the LE (limited edition) version was measured, again by both Stereophile and ASR, I would expect the results for the C3050 to be the same, as the so called LE version usually is more about aesthetics only.
SoundStageNetwork.com | SoundStage.com - NAD C 3050 LE Integrated Amplifier-DAC Measurements
NAD C 3050 LE BluOS streaming integrated amplifier | Stereophile.com