Rama - Orach Chaim 124:3 says that the one leading the prayers should not wait for the respected people to finish their Tefila. Mishna Berura 13 - says the reason is because of Tircha D'tzibura. Mishna Berura goes on and says that these days we do wait for האב״ד (this acronym is the Av Bais Din - perhaps extended to Rabbi or most Chashuv person in the Shul)
ועכשיו נהגו שהש״ץ ממתין עד שיסיים האב״ד את תפלתו
My question is - What is the earliest recorded point after the Rama that this changed, and we started waiting for האב״ד / Rabbi prior to repeating the Tefila?