Is there a din of donut or pizza shenisalem min hayain that concerns some? So, they are open on shabbos. The Rav Hamachshir presumably is aware of this fact.
Not every Rav Hamachshir or kashrus agency will give a hechsher on anyone open for business on shabbos, however, many legitimate ones do.
Lastly, Monsey Mom, if you have concerns regarding the kashrus, contact the Rav Hamachshir, surely the establishment has contact information for him. Why post this on YWN, what do you hope to gain from giving over this information?