I read your post 4 times, it's not clear what you want.
You want to make an angle from sheetmetal?
I'm not sure why you would roll an extrusion to make a radius.
I would also try the insert.
Also, make sure the tapped threads are clean. I have seen too many threads with metal bits in them from the tapping process that will cause the bolt to strip or get stuck.
I have seen young engineers switch careers, burn out, change from mech to other engineering, because they are taught GD&T and how to tolerance parts. They want to only design a 3D model and move on.
The ones I find that stick with it are the ones that are taught machining practices, they get...
I only had to do this once several years ago. We made a fixture from tool steel, sandwiched the sheetmetal with it, stressed relieved in oven. I don't remember temp/time.
If SolidWorks or something similar to complex, then anything may be too complex. A lot of small startups use Sketchup. https://www.sketchup.com/en/plans-and-pricing/sketchup-free?srsltid=AfmBOopW6jr78dsLI8d90N5FzWScmAWp8dJrvc4xbBUGSnULvY6UYicu