About the couple of times you have said "fully filled", is that a specific industry or engineering slang or term?

Maybe it was a bit too colloquial. I am not sure if this is very important. A formal term would have been "full propellant load." The phrase "fill level" is also used in NASA documents.

The question was whether during this test the stage was loaded with the same amount of fuel as for an actual flight, or only a small fraction of that.