Question

Hello Rabbi! And congratulations, belatedly.
On Sabbath 24b it says that the prayer leader who goes down to lead the evening prayer of a festival that falls on the Sabbath concludes only with “Who sanctifies the Sabbath,” without mentioning the festival.
Medieval authorities (Rishonim) and later authorities (Acharonim) inferred from the expression “prayer leader” that an individual praying alone cannot say it, and that it is said only in a quorum where a prayer leader is relevant.
The Rokeach brings from the Geonim that an individual may say it (I did not find this in the Geonic sources, but that is not proof).
I wanted to suggest an explanation for the Geonim’s reading of the Talmud, and ask whether in your opinion it is acceptable:
If the expression “prayer leader” had not been written, we would not have been able to understand that this is referring to the blessing of Me’ein Sheva, and we might have thought it was referring to the blessing “Who sanctifies the Sabbath” in the middle of the silent Amidah prayer. So the expression “prayer leader” comes only to exclude that understanding and to teach that this is speaking about the blessing of Me’ein Sheva. There is no need to derive anything further from that expression. And perhaps this is also how Rashi understood it there: “The prayer leader who goes down for the evening prayer — the one who recites the blessing of Me’ein Sheva, ‘Who acquires heaven and earth,’ ‘Shield of the Fathers through His word.’” From his opening words, it seems possible to understand that the entire significance of the expression “prayer leader” is only that this is referring to Me’ein Sheva, and not to exclude an individual.