Hope you both heal quickly.....
From what you've written, it sounds like you do a lot of peg scraping.
The more you scrape em down the less warning you get till the hard parts hit.
With a pillion's weight, the clearance is lessened.
So as I understand this, a hard part of frame hit and removed your traction and you low-sided.
The question that comes to my mind is how do you (or do you) shift your body weight while riding?
Do you lean weight into the corner...which keeps the bike more upright (and gains traction)?
Do you lean to the outside of a corner...which creates more lean, more chance to scrape (and reduces traction)?
Or do you keep body centered with bike, (which falls between the two above)?
If you already are leaning into the turns (left for lefts, right for rights), you may have no choice but to slow down (well you might file your frame down a bit in critical contact spots..... I'm not recommending that but I've seen others do it).
But if you're not already leaning body weight into turns, you have the potential to gain clearance and minimize scraping by shifting body weight.