fabie – “The words of Reb Moishe are, “I personally am Machmir, and a Ba’al Nefesh should be Machmir.””
But Rav Moshe did drink CS when CY was not on the table. So what does machmir mean and what does Baal Nefesh mean? It means if it’s convenient, use CY, but you don’t have to go out of your way.