I don't think so. I can't say for 100%, but I know on some tank regs, the fill nipple is on a specific port used only for input. I know you can swap the gauge and burst disk though.
If you want to set off and go develop some grand new thing, you don't need millions of dollars of capitalization. You need enough pizza and Diet Coke to stick in your refrigerator, a cheap PC to work on, and the dedication to go through with it. We slept on floors. We waded across rivers. -John Carmack