An aluminum prototype can help settle the questions that remain abstract in a render or printed stand-in. You may need to check a stiff bracket under load, the feel of an enclosure, a thread that will be used repeatedly, a heat path, or the fit between mating components. The useful part is the one that gets your team closer to a decision about the next revision.
That is why the first conversation should begin with the actual geometry. Wall thickness, pocket depth, corner radii, holes, threaded features, datum surfaces, and the way a part must be held all shape the machining approach. A material label alone cannot tell a shop whether the design can be made and checked as intended.
twentyfour26 keeps 6061-T6 aluminum in the defined machining cell so the review can focus on the work in front of you. When the part fits, the next step is a plan for stock, setup, tooling, and inspection. When a feature needs attention, the goal is a useful explanation early, while the design is still easy to change.