First off shout out to the customer service I called with a fitting question and they were amazing!!!
Second sizing/comfort
I bought the 2X/3X on recommendation if I wanted something to fit pretty loose. I am 5'10" 220lbs 46" - 34" - 48" and it fits me baggy but comfortably and I have no worries about it falling off my shoulders. If someone my size wanted a tight fit I'd recommend a size or 2 down