What to enter in Solar.Forecast "total modules power"?

It’s sadly really not described well.

For 16x400W panels, am I supposed to enter 6400 there? (which would be the theoretic peak DC)
Or something like 6400*eta where eta is efficiency … but how to choose eta then?

Or am I supposed to enter the maximum peak value that was ever produced? For example, on June 19 at 12:30 I observed the highest production thus far (1260Wh between 12:30 and 12:45, so 5040W).

Am I supposed to enter 5040W here?

Put in the rated peak power of your inverter if the peak DC power of the PV array exceeds it. Otherwise use the rated peak power of the PV array.

Is this supposed to be AC peak power or DC peak power?

I have Enphase IQ8 microinverters, how do I figure out “rated peak power of the inverter”? Datasheet states 300VA (note, this is VA, not Watts). Is the correct value to enter 16*300=4800 then? That can’t be exactly right either because as stated, the max I ever produced is 5040W which is larger than 4800…