Same with the Shabbos Mode oven; while Poskim can disagree, you can’t put down the numerous Poskim who endorse it and the programed technology that permit its use halachically on Shabbos and Yom Tov: Shabbos- use of warming drawer for food left in it before Shabbos; oven lights are cut off; 12 hour turn off is cut off. Yom Tov- temperature and other oven displays are gone; 12 hour turn off is cut off. It seems that zilzul Shabbos is not an issue to the Poskim that are matir the Star K (Rav Heinemann) Shabbos Mode oven.
And what about Rav Moshe Feinstein’s chidush and Psak that one can even turn OFF a gas range completely on Yom Tov, l’chatchila! Shocking? Well, many thousands of his talmidim, his family, and those from the lower East Side do it. It seems that zilzul Shabbos was not an issue to Rav Moshe when he felt there was a valid halachic reason to permit it; while the use of Shabbos clocks for the most part were problematic.