Been busy but finally got around to it, interesting stuff on VGs-- My former employer had a STOL equipped mixmaster with VGs being part of the kit and it cruised about 10K faster than the stock airplanes we had so the performance claims might be pretty accurate,
I'll bet when you're lightly loaded in the 1900 that you accelerate through Blue Line in the rotation--too much performance to be held on that long? (or play like a wheelbarrow )
My guess i
Even heavy I can't imagine trying to hold the thing on the ground until Blue Line. At max gross on pavement we in the process of rotating at 108 kts. Blue line is 125.
The 1900 likes to fly and the engines produce a ton of lift on the wings. We're airborne before we actually get to blue line, although we generally get there fairly quickly.
We're also topping 1200 lbs / hour of fuel burn on takeoff (600-700 a side).