In this question How does Shabbos/Yom Tov mode on a stove work? it discusses how the Shabbos / Yom Tov mode works. I have recently heard that there are Rabbis that do not allow using this mode. Does anyone know who is in favor and who is against?
The answers in the question you linked cite Rav Heineman b'shem Rav SZ Auerbach as an authority who's lenient and Rav Shlomo Miller as opposed. I believe Rav Nahum Rabinovitch of Maaleh Adumim has also said one can rely on Rav Heineman's leniency here (though I think generally he is reportedly not so convinced of the reasoning behind Tzomet's grama machines).