[Avodah] Ashkenazi Minhag

[Gilad Field]

I was skimming through the Tashbetz  (not the Shutim by the Rashbatz -
the one authored by a talmid of Maharam Rutenberg and details the
minhagim of the Maharam, as well as other ashkenazic rishonim).  He
mentions a number of interesting things there (available on
hebrewbooks.org) , one of them is (siman 245) what point the shaliach
tzibur begins shachris.  the current minhag, that I am familiar with
is on shabbos he starts with "shochen ad" and yom tov he begins with
"hakayl b'samuos uzecha" and yamim noraim with "hamelech".

Apparently the earlier Ashkenazi Minhag  was to start a different
point for each yom tov, as follows:

shavuos - hakayl b'samuos uzecha
sukkos/shmini atzeres - hagadol b'chevod shemecha
pesach - hagibor lanetzach
rosh hashana/y.k - hamelech

I assume nobody continues this minhag today - please let me know if I am wrong.
What I would like to know, if someone has done any research into
Ashkenazi Minhagim, is why some minhagim are no longer practiced (in
general, but also this one specifically).

Are there any recommended sources on this topic?


Gilad