I would expect a dealer to always disclose this information. I see them do it frequently. If I thought someone was I would ask a none threatening / question about it.
Actually I did the other day. Someone made the most absurd claim about cost having noting to do with performance. I just asked what his equipment was. He then said he manufactures it… and disclosed everything.
Vested interest makes a difference. When I got out of grad school I understood the concept. But, I always thought it was a very conscious process… it is not. I then spent nearly 40 years managing… line people, world-wide projects, and working among executive teams… it is not… it is typically 100% subconscious and frequently the higher the “intelligence” of the person (frequently accompanied by low EQ… and low self examination) and it is 100% invisible to the person. It was for me in early life… it takes real work to see it… and a high EQ. This is why it is such a big deal. Vested interest completely changes your values. Also drives a lot of egos on this site… because folks worked hard and value the system they put together… so the KNOW.