You can just set Windows to output 192 kHz and see what the receiver does. Mine works with stereo, but with multichannel it displays 96. In Pure Direct mode, it just says "PURE DIRECT", but I think it's safe to assume that in this case it's not downsampling. Same behavior for 176.4 (it downsamples to 88.2 in this case).
I'm also not sure how exactly these DACs work, but I've been told by someone who knows better that DACs usually oversample to 352.8 kHz or higher, so we can't really be sure what's really happening inside the DACs unless we have all the details of them. I think that's what the "8x oversampling digital filter" (44.1 x 8 = 352.8) meant on my old Discman. So if these assumptions are true, my receiver would be downsampling to 96, applying DSP and then the DAC upsampling to an unknown sampling rate in order to convert to analog. So, I just fully trust the engineers that design these DACs to do what's better.