Is it correct that on the night of Rosh Hashana you are supposed to make the bracha and cut the upper Chalah? Why?

Indeed Mate Ephraim rules that the upper Chalah should be cut first on Rosh Hashana(583:1). Shulchan Aruch and Remah (O.H. 274: 1) rule that on Shabbos night one slices the lower Chalah while during Yom Tov one cuts the top one first. Remah adds that the reason is based on Kabbalah teachings. Mishna Berura (4) mentions that this is due to to the fact that words ‘Lechem Mishne’ are mentioned by the recollection of the Mon. He quotes, that the Bach questions why go for the lower Chalah, if by avoiding the top and closest one, we could be violating the prohibition of ‘Maavirin al Hamitzvos’ or neglecting the mitzva nearest to us. However. Taz corrected the above by advising to place the bottom Chalah a bit closer to the one cutting. He adds that one may take the upper one at the time of reciting the brocho and then places it bellow and cuts it. Horav Shlomo Miller’s Shlit’a opinion is that as usual one should follow the traditions of his family.