not really risky, but only risky from the aesthetic pov, because a lot of the results can "chimpmaxx" and not really improve the aesthetics, idk I've almost never seen an actual facial improvement from mse, like this guy, he looks chimpmaxxed after
Lower jaw definitely but not entirely sure if u need bimax or genio. lower could be enough. maybe some mandibular widening (msdo) but u would need to combine that with mse likely so it's not worth the risk