Just to review, as some of you may know, I use the HDMI output to connect to my A/V receiver.
I'm currently running B2B Mar 17 2020 software. I have not updated to the most recent as I am waiting for a fix to the random play problem that was reported recently.
I just started a song to playing. Then I checked to see what the Jack Sense was. It was ON. Then while the song was playing, I changed it to OFF, the music continued to be heard. Then I changed Jack Sense back to ON, music still played. So Jack Sense has been On this whole time with no ill effect on music. However, I don't have anything plugged into the Line Output/Toslink jack.
So, while the music was still playing through my speakers, I plugged my headphones into the Line Output jack, Jack Sense ON - no change. So I changed the Jack Sense to OFF - I heard a small pop in the headphones, but music continued to play through the speakers and not in the headphones. Then I changed JS back to ON - still no change.
So, as far as I can tell, Jack Sense has no effect whatsoever on the HDMI output, which is what I would expect and is as it should be.