Early Shabbos minyan Brooklyn

Sha’arei Shalom (Ave P and Madison — not too far away) has a Mincha minyan at 7:00 pm.

The Wolf

Damoshe
We are all familiar with the mishna brura on the subject
Yet many are not makpid including some very chashuv kehilos

DaMoshe wrote:
“There’s a big issue with the 7:00 early Shabbos minyanim. If you’re going to daven Kabbalas Shabbos before shkiah, you need to daven Mincha before plag. Plag today in Brooklyn is 6:22, so Mincha starting at 6:10 or so should work.”

Actually davening at 7:00 is much better than davening at 6:10. The reason is that by davening at 7:00, you are davening mincha before the Magen Avraham’s plag and maariv after the magen avraham’s plag, so there’s no issue of a tarti disasri. If you daven at 6:10, it means that you are davening Maariv before the Magen Avraham’s plag. The Mishna Berurah isn’t machria which plag is lihalacha. As such, by davening Maariv before the Magen Avraham’s plag you are making tens of (safek) brachos livatala. It is better not to daven at all than to daven Maariv before the Magen Avraham’s plag, unless you are a Granik.

Magen Avraham plag is a misnomer.

N0mesorah, the Mishnah Berurah disagrees with you, and says we do worry about tarti d’sasri.
וי”א דבצבור יש להקל להתפלל מעריב מבע”י אף אם התפלל מנחה אחר פלג המנחה ונ”ל שאין לסמוך על זה רק כשהוא מתפלל מעריב עכ”פ בבין השמשות ובשעת הדחק