FWIW:
I had the same thought some 10 years ago... after all, I already owned most every size EMT and rigid bender made. How hard could it be? Well, after an attempt to bend the tubing cold with NO success, I then filled the tubing with sand and used massive quantities of gas to heat it during the process. I finally made some bends, but they weren't pretty. Not saying it can't be done with a conduit bender, just saying that I tried and couldn't get satisfactory results. Give it a try yourself. I think you'll find a new appreciation for the tensile and yield strength of 4130. I know I did!