1) Someone started milui ve-irui on Friday afternoon, April 15, meaning that the 72 hours are finished after the time of issur chametz. Would that be a problem? The utensils are glass pitchers that mostly were used for water, but sometimes other drinks.
2) I note that you say that warming trays (or drawers, I think is what you were referring to) cannot be kashered because they do not get even to libun kal. Would this be even according to the shita of R’ Aharon Kotler, z’l, who seemed to hold that ke-bol’o kach polto applies even when that the degree is not reached, as long as it is never reached. Similarly, I have read that one of the svaros behind milui ve-irui is ke-bol’o kach polto. Does that not demonstrate that the sevara is not dependent on heat degree? Finally, even without these arguments, why would there be such an issue, considering that the usual use of a warming tray is for pots, and there is no transference of taam from kli to kli blo rotev? (Even though some places is sounds like that is only bedieved, the MB by chatzuba seems to indicate otherwise (I am quoting only from memory here).
Thanks for any light you can shed.
1. The milui ve-irui is fine, even if it is completed after Pesach has commenced. This is all the more true because the pitchers are glass, and their main use is water, and they are only used for cold drinks, which provide several reasons for general leniency. In principle, hag’alah can also be performed on Pesach itself, as can the milui ve-irui process.
2. I am not sure of the type of hot tray or plate that is being referred to. Because food spilling on hot trays/plates is common, these require kashering. According to most authorities, the sevara of kebol’o is said on different types of belios (keli rishon, and according to some irui keli rishon), but not concerning the degree of heat. However, some authorities write that the sevara applies to the temperature of the beliah, and that one may heat to the same temperature at which the beliah was absorbed. One may rely on this opinion under extenuating circumstances.
See Minchas Yitzchaks 3:66; Arugas Habosem 119; Kitzur Shulchan Aruch of Rav Pfeiffer Vol. 2, chap. 12, Biur 5. There is more to write here, and beli neder, I will fill in more sources at a later time.