Just measured our more recent Ace Supreme and it is 2.4m from the rail to the ground. That's 11 inches higher in old money.
Thinking about the two porch awnings we have ( Sunncamp 390 & Outdoor Revolution Easiporch), I don't think they would work if they were lowered by 11 inches. There is some flexibility for sloping pitches, but closest to the caravan side, I think at 11 inches shorter you would struggle to get tension in the rubber anchor straps. From memory they are only around 6 or 7 inches long, so the bottom edge of the awning sides would be touching the ground with no means of keeping it taught.