macOS Sonoma in internal Fusion Drive

I'm using an external SSD Drive with macOS Sonoma.

NOT using the internal original iMac's Fusion Drive.

I want to "ignore" the internal original iMac's Fusion Drive from any action.

So if I'm formatting the internal Fusion Drive ( Container Disk2 ) . Will the macOS also delete ( In that internal drive) ?

( I've download the macOS Sonoma to the external drive also. )

internal original iMac's Fusion Drive :