32 BIT is only going to affect the signal to noise level.
24 BIT has a signal to noise level way beyond what the ear can decipher so 32 BIT is just a spec game.
Maybe. And I imagine they use 32 bit's floating point properties (if I understand them correctly) so people who listen to music via their computer or use other forms of digital attenuation, such as plugging their DACs directly to their power amp (not my bag but it takes all sorts), don't experience any signal degradation when they change the volume.
I would say the DVD player is sounding deferent for reasons other than the BIT rate.
Maybe you're right. It could be something to do with the HDMI. I just tried again it now to make sure and playing that album via the Panasonic UHD blu-ray player definitely sounded less compressed than via the BDA's Pi. The sound from the BDA-3.14's streamer was good, I hasten to add, just fatter. Maybe I need to compare and contrast a bit more..
Anyway, I await your engineer's advice whether 32 bit compatibility could be added via a firmware update or something similar.