There are two paragraphs in the Torah where the word mezuzos appears. The first, in Vaeschanan (6:9), is written with a kubutz (no vav)- מְזֻזוֹת . The second, in Eikev (11:20), it is written with a shuruk- מְזוּזוֹת.
Rashi to 6:9) writes that lack of vav hints that we only place the mezuza on one of the doorposts.
Some chumashim with Rashi that I have looked at have Rashi with a different text- מְזוּזת (maor mikraos gedolos) or מְזֻזת (artscroll) - implying that the grammatically singular writing hints that we only place the mezuza on one of the doorposts.
Others (newer version of the "shul chumash" and this older version of mikraos gedolos) have our text (מְזֻזוֹת) implying that the distinction is made between 1 vav and 2.
Does anyone talk about this Rashi or about the vav difference?