Well, Angel, did you ever figure out how to do bumps of your sneeze-inducing stuff at work? General consensus was a strong NO on plastic bullets. Also, too, doing coke on the job. Adderall will help you stay awake on your non-coke days, but you need to be thinking about slowing that habit.
OK, 1.5 grams over four days isn't the stuff of '80's villains, and I know it's an energy-intensive job. But you're using recreational amounts to get through the work day. It's not sustainable.
I don't think it matters what order you try the XR or IR dose when you only have one of each. You said previously you tried meth and hated it, so you may not care for Adderall (it certainly wont replace what you're getting from coke); but it's a much better option for occupational energy, and one you might think about subbing. If nothing else, compare twice-a-day-tops dosing to how often you run to the bathroom to keep the coke going. Each work-place redose is a chance of firing or imprisonment.