I use the aluminum angle as a heat reflector, 15 seconds to scorching hot, then I hand straighten.
The roller thingie is a compression arrow straightener that works really well ($35) but a screwdriver shank works just as well, anything to compress the fibers. I use it to take out the last of the bends after heat straightening, I work the ramrod cold at this point.
I put the high point of a bend facing up, pull ever so slightly up on the ramrod and roll the straightener over the bend pushing it down. This is a finesse type of thing, it is easy to make the bend go in the opposite direction and have to start over