Jordan…
I’ve been looking into the same issue you questioned, with regards to stem mount of 310xt.
Have a look at this guy’s review. About 3/4 of way down he shows some pics of the quick-release mount, and it looks like a stem mount will be fine.
http://dcrainmaker.blogspot.com/...in-depth-review.html
Yes, the quick release mount rotates. So you can simply grab a screwdiver, undo the screw and then adjust it 90* and then tigthen again. At the end of the post I included a big gallery of picture (over a 100), and there’s a ton of the quick release kit in there all taken apart.
I put it on both a stem, as well as then attached it to the outside edge of my handlebar area. Also tried it up on the actual aerobar too - a bit funky there, but workable if you don’t have an aerobottle.