Arduino for STM32

Thanks.
What is the source of the drop down list for the available generic cards?
I looked where (I believe is) the configuration files:
AppData\Local\Arduino15\packages\STMicroelectronics\hardware\stm32\2.9.0\variants\STM32H7xx
And I see more folders for 7A than there are in the list. Actualy I see ...

I am trying to use a NUCLEO-H7A3ZI-Q board with the Arduino IDE.
Since this specific board is not supported I am using the "Generic H7A3VIHx" board.
I am trying the simplest BLINK sketch using PB0 for the onboard led.
Everything looks fine - builds the code, attaches to the on board ST-LINK and ...