I do the same thing with the bolts... but I also have some velcro sewn into the back and front of my jumpsuit to help keep the armor from sliding down.
I've just learnt about the Fett thong. It's a requirement for 501st clearance (UKG at least). For me it serves no purpose. I've poppered my Bobamaker butt plate and cod onto the flight suit and with the girth belt to secure it, it fits fine.