“This one is universally (AFAIK) accepted by ???????.”
And *that*, not the codification of the Rema, is why Ashkenazic Jews don’t eat kitniyot. Minhag is important.
“Because if the difference is small enough, it is worthwhile buying a new one. “
Dishwashers aren’t that expensive compared to the cost of a new house. It might be worth it.
Kashrut is the major divider among Jews today. I am glad that I live in a neighborhood where if you are shomer Shabat, people trust your kashrut.