Years ago I mounted a cheap red dot onto a carry handle adapter (standard see-through type). I thought it was pretty jingus the way it sat so high, but I zeroed it in at 50 and it actually shot really well. I did always have some trouble keeping it tight, but I put a star washer on the screw and torqued it a bit with pliers. My main concern always was, with the taller sight height it would be very important to keep the weapon vertical i.e. not leaning to the side. To me that seemed like it would be very inaccurate, but the way a rifle tucks into your shoulder, and with the pistol grip also, it seemed to naturally fall into place, repeatable as we say. As for the weld, it was kind of in between cheek and chin, let me just call it a jaw weld. You know, for plinking with a red dot, I never had to get too uptight about my jaw weld, just took a quick look down the hole and bang. Now for more precision shooting, I definitely like a firm cheek weld, and a gooseneck would be better, but that I have never used.
EDIT: I would like to add one thing, I used this set-up exclusively for off-hand shooting...bench & prone I found it too high to be comfortable.