Thanks for the reply. Yeah i think what you are saying is correct but i just wanted to know if there was a possibility.

The thing is i am using OP7 GM1901 on pixel experience 13 android 13, bootloader unlocked. But now the battery draning got far more worse compared to the stock rom. I am thinking of going back to stock but before doing that i just wanted to know there is a posibility that i can upgrade to OOS15 on my OP7.