I may have gotten myself in a spot where I'm trying to take direction from too many sources (or misinterpreting).
I just took Dan Miller & Tim May's workshop on technique, where they spent a good bit of time on rest strokes, alternating strokes, positioning & other items. That was great. I came away confirming that I have a lot of work to do, particularly with regard to developing strong alternating pick habits. There was a fair amount of emphasis placed on right hand technique.
I also picked up a copy of Marilynn Mair's "The Complete Mandolinist." In it, she advocates for the upstroke having the pick strike only the bottom string of the pair. That's the first I've run across this, although if using alternating strokes, I think it makes sense. By limiting the attack on the upstroke, I would imagine that it helps in de-emphasizing the off-beat. She's also clearly focused on more classical music and less so on bluegrass.
My question is: does hitting only one string on the upstroke apply universally, or only in some cases?