Normally in thin sheet metal manufacturing you can get away with using the inner surfaces for bending, but you have to check with your manufacturer (this is what was used in the example video). Can you post one example of what you are trying to unroll? depending on how it looks it might be doable with a script. Manually it would be extracting the inner surfaces > join > unjoin some edges > unrollsrf
One way I can think of is exploding the object, select objects with small area (using a script) and delete these then rejoin and select the smallest part (which would then be the inner surface)