Dear Benignuman and Rabbeinu Sam,
I was heavily edited as you see, I’ll change it up a bit. I disagree that the concept of hefsek applies between the chupah and yichud. Too many kushyot can be asked and inadequately answered.
As an example, I always wonder on Purim morning when the gabbai announces to keep mitzvos hayom in mind when the ba’al koreh makes the Shehecheyanu on the Megilah. Isn’t this going to be a colossal hefsek? My answer: no, there is no hefsek. Apply to many other situations.