I’m a quiet pooper too...but I also have a sensitive stomach...sometimes I just eat something that doesn’t sit right and it’s almost damn immediate that I have to exercise a demon...like chipotle is a good example...I can’t leave the restaurant...I immediately gotta blow the lid off the porcelain god...
as for shy pooping I try not to drop or push until someone flushes...that way they don’t hear the little dollop splash as my turd tries to hit a triple 3.0 in the shit olympics.