Mod 42 – “The bread that the OU gives hechsherim to is pas palter, bread baked commercially, which is muttar to eat. There is a chumra not to eat it, some people follow this chumra all the time, some follow it only on Shabbos and Yom Tov, but it is only a chumra, halachicly it is completely muttar.”
Wrong – since you mentioned the OU. The OU claims that all of their baked products are Pas Yisroel because it’s their policy to have the Maschiach light the oven. So there is never a reason not to eat their products even during the Aseres Yemai Teshuva.
(I personally doubt it’s every single time, but it’s probably Rov.)
This I heard from s/o who works for the Vaad Hakashrus of Balto. (I guess this only applies to Bishul because I can’t see it applying to baking.) The Rav Hamachshir (you know who he is) holds that if the Maschiach turns on the light in the room -this is enough not to be Bishul Acum because the light adds a tiny bit of heat.