DSD and resample option

after reading many posts there are a couple of things I’m still confused about .
I have a USB DAC connected to the rasp 3b+ which is capable to play PCM up to 24/192.
I set Volumio as following:
I2S off
Direct DSD
No mixer
No resampling.

My question is, what exaclty happens at playback bit level? I guess the stream is converted to PCM, but is it resampled or not?
I tried to play flac files claimed 24/352 downloaded from 2L. My DAC shouldn’t be able to play them, but I can listening without any problem! I also tried to enable the resamplig switch in Volumio, with Native options for sampling rate and bit depth and still I can play the 352 kHz file. The same happens setting DOP (DSD over PCM).
So it is not clear to me how the software make these conversions.
I hope someone can explain