In working with the sheet metal pieces, I've developed a system of modeling and checking fit without having to cut metal. It's pretty common in the EV world to do Cardboard Mockups, but here's my take on it for sheet metal.
Model the sheet metal part
Use spray adhesive to adhere the Print to some Posterboard and and trim the outer shape. It's important to let the glue dry overnight while laying flat. When dry, use a straightedge to make straight creases along the fold lines.
Using the Posterboard model, I can get a feel for how things look and fit. Obviously, it's a lot easier to make adjustments in paper. This is the 4th verision of this particular paper part, and I'm finally ready to cut the real thing in 3/16 Aluminum sheet (5052 alloy).