I think it’s all good.
Some can hear a difference, some can’t.
For some it’s important, for others it’s not.
Not sure what arguments achieve on these topics.
🙏
As a rule of thumb a SS amp should have a lower ohm rating than the cab(s) its driving.
So the 4ohm amp is fine with the 6ohm cab (or total cab configuration).
An 8 ohm amp is not so fine with a 6 ohm cab (or total rated configuration).
I am no physicist though.