Also, just to prove that you really do know nothing: The rema himself brings 3 rishonim how hold like that. And I’d likely find more if I went through them.
And I’d like everyone to know, that this is not an isolated incident here. This IS one of the basic YCT sicknesses. They–quite like Conservative–think they can be machria between the rishonim, and that any psak since the time of the gemara is non-binding on them because “it’s just a minhag”. They are literally not practicing the same religion as us.
I’m glad we brought this example out. Thank you for cooperating so well.