People with bad manners on land won’t change when they get in the water, side mount is not as handy as back mount, if you can handle the weight of a twinset then back mount is the simplest way to do it.I've been buddied up with divers on recreational dives who use sidemount. I just find it strange they want to use sidemount on NDL dives but it's not my place to judge that. On one of my dives I was taking a photo and got smacked in the head by a tank from by my sidemount dive buddy who decided he wanted to see what I was taking pictures of.