Quick tip: build multiple variations at once to shorten your development cycle.
If you have several options to test of the same base part, but few different details, just CAD them all up, and prototype them all at once.
Save days of waiting around for parts to test.
If you order from a service like Xometry, the volume discounts more than compensate for the time savings waiting around. Plus, the box is shipping anyway, might as well throw in a few extra parts.
Your development budget will thank you.