Kaddish related minhogim

The Minhag is to say Yisborach in every Kadish.

Michael

The psukim in between the Kadish are not mentioned in the Rishonim, but were brought in the Siddurim from the first print and on. The source for them is not too clear, and some are noheg to say them, some are not.
As for the Ve'ato Yigdal No - it is brought in the Tur to say before every Kadish, but because of "Hefsek" it is not said before most of the Kadeishim, only before Kadish Tiskabal. Although this has a very clear source, it seems that even less people follow the minhag to say it.

Michael FRBSH

In Copenhagen, they had a choir singing the psukim Kabel Berachamim etc. Yehi Shem etc. with proper notes for it.

Many Thanks to Mr. Jan Meyer for this piece of information, and for giving us the Copenhagen notes!

Michael

The Chavas Yo'ir (in his book Mekour Chayim siman סו) says that one should say Yisborach even in the middle of Birkous Krias Shma. (But the Divrei Kehillos pg 50 says that he assumes one should not say Yisborach in Birkous Kri'as Shma).

Michael FRBSH

R' Zalman Henneh changed the Nusach from Yisgadal to Yisgadeil. The Pri Megodim and the Gr'o accepted this change. In Ashkenaz R' Zalman Henneh's changes were not accepted.

Michael FRBSH