I bought a pair of those eastwood hand fired panel flangers 30 years ago, I found they got more use and are better suited as clamps.. Years ago I bought a Mac Tools air flanger yes it was a bit pricy but sure made things much nicer to work with..
If you flange a panel that gets wet or will hold dust/dirt make sure the lap is pointing down on the backside .
In other words make sure water will run over the joint not puddle into it...
These are what I have
https://www.mactools.com/en-us/Power...nd-Flange-Tool