Impact of integer mode on DSD material

Hi,
I would like to understand the underlying mechanism of enabling/disabling integer mode for DSD material on Mac Coreaudio. I use Roon’s DSD to PCM 176 conversion. After conversion, believe the internal word length should be at 64bits float. Since my hardware maximum supports 32bits, so if i enable integer mode, the word length will be dithered to:
-32bits integer or
-32bits float or
-24bits integer within 32bits package?

I hear sonic difference between enable/disable integer model, so would like to know the underlying mechanism.

Thanks!

Kevin