export with in out set with audio time units

timeline:show audio time units...

 I always thought that premiere would simply default to the nearest frame for setting the in/out for a whole project, but was just zoomed right in on the timeline and saw it was not.  My assumption then was that it would simply start and end from the nearest whole frame, but now I'm wondering if it's not set to start at a whole frame that it does some janky frame resampling (frame sample/frame blending)? Anyone know for sure?  I always edit with time units showing, because I do a lot of re-editing music.  If I need to switch that off before rendering: 😬 I wish I'd known that 5 years ago