just my hapence, You cannot say that OY is made up! in shabbos morning shachris we say Yismach Moshe. It was written as a rhyme. That’s why we add Koroso LOY even though it isn’t grammatically correct. Now look carefully, it only works if you say the cholam as OY.
Put that in your pipe and smoke it!
Bottom line is, say it as you were taught and dont change. If you do, you could be passeling all your krias shma’s from the previous years.
The Rosh Beis Din of Johannesburg, Rav Kurtstag, was brought up in Tel aviv, and was taught to read in the ha’avara of Tel aviv, which is most similar to sfardi. I dont remember who the godol was, but he was told to keep to it.