not sure where you heard that because “This parameter is named static because it cannot change at runtime, it can only be set in the Material Instance Editor.”
This is because under the hood it will generate a new material when a static switch is ticked.
look at the static nodes here:
If you want some more in-depth optimization info, you can check this document I made a while back:
Edit: you could make a new master for each switch, but that can also increase time spend managing each master, especially annoying if you need to change the same values in each master.
Sure, a smart material editor person sets up material parameter collections for such things, but you’d need to know about them and prepare them ahead of time.