I live for the CABE
I like the pipe expander idea. They have manual ones you can probably pick up cheap, but I don't know if the go that small. Kind of a round wedge type affairThat steel is 1010. It is on par with rebar or melted car bodies. Not an alloy, just a cheap, easily welded steel. It is easily worked for a minor bend like that.
You shouldn’t have to heat it to bend it to where you need it to be. If you have a custom exhaust shop with a hydraulic tubing bender, close by, you can probably slip him a few bucks, and he will use the expander collet and make the frame perfect. But, working it with hand tools will work, also.