"Are there any meforshim who see the ehyeh in 3:12 as the name?"
Rashbam and Abarbanel. ( This comes from the commentary in the Gutnick Chumash pages 356-357)
Also, in 3:15, L'olam is missing a vav. This implies that the name ehyey is a concealed name. ( This comes from the English translation of Mikraos Gidolos, Judaica press, The footnote cites ...
This subject is discussed by many meforshim, particularly within Chassidut.
The first name pertains to the final redemption (which is why it is being utilized to address Moshe in the first redemption) and also precedes creation (meaning before the Kav enters the Makom Panoy and what follows afterward).
Regarding your observation that in Shemot 3:12 this ...
Or HaChaim on Shemot 3:14 makes this point:
ושם זה כבר רמזו אל עליון בנועם דבריו באמור לו כי אהיה עמך
The Supernal G-d had already hinted at this Name with His pleasant words when He said to him, "For E-hyeh is with you".
From what I could quickly gather the first reference to (אדון(י is when Sarah laughed to herself after overhearing what יי said to Abraham in Bereshith 18:12. The English translation uses a lower cased "lord or husband" as translated in my Chumash. In modern Hebrew אדון can be used for the English "sir, mister, master, lord." If you understand the נְקֻדּוֹת (...