Should the speaker in "Meeting at Night" be considered an extension of the author?

Browning in 1833 anonymously published Pauline: A Fragment of a Confession. Drawn from real-life personal anxieties and passions, it received some praise but scathing critical comment from John Stuart Mill. This permanently impacted Browning's poetic mode of expression and sent him on the quest that eventually resulted in "dramatic monologue." A small quotation from Pauline follows.
To cast away restraint, lest a worse thing
Wait for us in the darkness. Thou lovest me,
And thou art to receive not love, but faith,
For which thou wilt be mine, and smile, and take
All shapes, and shames, and veil without a fear
That form which music follows like a slave;
And I look to thee, and I trust in thee. (Browning, Pauline)
Browning opted to find a biography-neutral poetic mode and never wrote confessional, introspective poetry again [although American poet Walt Whitman succeeded about twenty years later in 1855 to publish even more highly introspective and confessional poetry in Leaves of Grass]. In Browning's letters to Elizabeth Barret, who became Elizabeth Barret Browning, he said, "all my writings are purely dramatic as I am always anxious to say."
While it is tempting to think that "Meeting at Night" represents a scene from Robert and Elizabeth's romance, with the poetic persona being a representation of Robert Browning himself, we have his word for it that his poetry is dramatic, exploring the human spirit's "layers of ice and pits of cold water," without confessional introspection, thus communicating nothing biographical to the reader:
"I am utterly unused, of these late years particularly, to dream of communicating anything about that to another person (all my writings are purely dramatic as I am always anxious to say)...." [Letters 74]
By way of confirming the conclusion that there is an absence of biographical quality in "Meeting at Night," Browning alluded to this non-biographical poetic mode by writing in the dialogue of The Ring and the Book, "I can detach from me." Consequent of these considerations—unless we want to disregard the truthfulness of Browning's letters—it is a mistake to think of "Meeting" as depicting in any regard the romance between Robert and Elizabeth. We must accept that the man "with pushing prow" quenching "its speed i' the slushy sand" is a dramatic creation of Browning's poetic inspiration: The poetic persona in "Meeting at Night" is not Browning; he is an immortalized dramatic character.