>> Divrei Chaim says sefard not to ashkenaz
I presume he means Chasidic nusach, not nusach Sefardim. I think we need to recognize this as it is – innovations, not supported by previous sources. It may or may not be obvious to the reader when sources are quoted in a line without times. MA (17th cent), Pri Megadim (18th), Diveri Chaim (19th).
Also, according to the summary of the letter in YWN a couple of years ago, Divrei Chaim seems to recommend the practice (a) for refined people, (b) trusting the gedolim of the generation
>> anyone whose soul is refined can rely on the leaders of the generation,
Interesting, if we accept that Chasam Sofer was a major innovator of the notion of Daas Torah, then here Divrei Chaim is using DT to overturn Chasam Soifer stand on Tefilah (“with all due respect”, I mean Divrei Chaim to Chasam Soifer). “Refined souls” footnote seem to be forgotten also, as now it is nushach recommended to the whole community. Interestingly, I don’t think Sefardim proper, at least in our times. think that it is good for Ashkenazim to switch Nusach the way (some) Chasidim do.