I had a really great customer support experience with Dinotte. I have a Dinotte tail light which came with a generous supply of mounting brackets for the seat post, but I needed to mount it on the rear rack.
I called customer support, spoke with Steve, who said he thought he could 3-d print something that would meet the need. I received it in the mail in short order. I was really impressed. My expectation was that when you spend bucks on a gadget, the non-standard mounting bracket you need should be low-cost, and that's generally an OG mindset, but they just mailed it to me. These Dinotte folks earned my loyalty forever.
Also, it's my first real-world use of a 3-d printed piece.