tefilla - A Lubavitch custom of reciting zecher and zeicher in "Ashrei"?

My cousin, a Lubavitcher, says both zecher and zeicher (that is, both זֶכֶר with a segol and זֵכֶר with a tzeire) in "Ashrei". I noticed this when I visited him a good few years ago, and assumed it was minhag Lubavitch. In the intervening years I've prayed a bit more in Lubavitch synagogues and have never noticed anyone doing the same, so finally got around to asking my cousin why he does so. He replied that, although it's not in any Lubavitch sifrei minhag, the last Rebbe did it, so he does it.

My question is: Is he right that the last Rebbe did it? If so, is that a good enough reason (from the perspective of a Lubavitcher) to do the same? If not, why might someone; alternatively, if so, why doesn't every Lubavitcher?

Answer

There is a booklet called Minhagei Melech that purports to collect all of the Lubavitcher Rebbe's customs; it states (pp. 28 and 34) that he indeed repeated the word with both vocalizations.

However:

1. 
   

   It's questionable how reliable these reports are (not just the ones in MM, but more generally, oral descriptions of what the Rebbe said or did); in some cases there are contradictory reports. (I don't know whether that's the case here, though.)

   
   


2. 
   

   There are practices that are known to have been specific to the Rebbeim, and not meant for the general public. (A few that I can think of: not saying tachanun on 7 Adar; reciting the Ashkenazic (longer) haftarah for Bereishis in a leap year; and giving shallach manos to a Kohen, a Levi, and a Yisrael.)

   
   

   Generally speaking, the official Lubavitch minhag follows what is written in Sefer Haminhagim (which underwent review by the Rebbe before publication, and much of which is based on his own earlier writings). In this case, Sefer Haminhagim has the correct vocalization as zecher with a segol; this comes from Hayom Yom (which the Rebbe compiled), entry for 11 Iyar. So even if he did say "zecher" with both vocalizations - in the absence of any evidence that this was meant as a template for others to follow, we might well assume that this was one of the Rebbe's private minhagim.