Aleinu on Yom Kippur

We (Zilberman minyan in the Old City of Jerusalem) davened Vasikin this morning (Yom Kippur) with no piyyutim (GR"A orientation minyan) and finished musaph at around 9:15.

I maintained that one should say Aleinu as one does after every tephilloh. The opposition pointed out that it is not in the Machzor. I said that the expectation was that one would be in shul davening all day with no breaks, and just like we don't say Aleinu between musaph and shacharis (or vice versa), one wouldn't say between musaph and mincha if there were no break, but if there is a break, then one should say.

In this same vein, in Rav Breslauer's (z"l) shul in Washington Heights, when mincha and ma'ariv were said together, there was no Aleinu in between.

Is there a specific minhag regarding Aleinu on Yom Kippur?

Tsvi Rogin

The Gra actually held to say all the piyyutim on the yomim noroim, i.e. both those of the birchos krias shma and those of shmone esreh, as can be seen implicitly from the ma'aseh rav and explicitly stated in Sh'eilos Usshovos Meishiv Dovor (written by the Netziv). The only change he advocated was to move the ofan of Yom Kippur to CHazaras Hashatz before "l'yoshev t'hillos".

Melech