There are really only three ways to make a solid thing: cut it out of a block (subtractive), pour liquid into a mold and let it form (molding/casting), or grow it layer by layer (additive). The trick isn't geometry first, it's count . Cutting and growing barely care about volume; each part costs about the same at one or a thousand. Molding starts brutal (you pay for a steel mold up front), then every part is almost free.
Somewhere there's a break-even; for 5,000 brackets you're well past it. Count picks the neighborhood; then geometry and material pick the house. So you don't pick a process, you pick a pairing , and justify it by beating the alternatives on the requirement.
▶ Live · scrub & hover — the cheapest process depends on volume — printer for a few, mould for a million