The Caravan was modified with the addition of a tailboom, belly pod, and wingtip booms for survey work. These required STC approval, thus flight testing. In addition to the stalls, and handling, I flew about six hours of "shaker testing" where an electric motor powered eccentric shaker shakes one wingtip pod at different frequencies, and at increasing airspeeds to investigate flutter resistance.
The spin resistance rather than flying actual spins was based upon agreement between my client, and Transport Canada, based upon my recommendation. In my past experience flying spin tests on modified Grand Caravans, I found that although they can be recovered as described in the design requirements, it's often an exciting ride, approaching Vne, and more than 2G in the dive recovery. With a forward C of G, when spun, they recover going close to straight down, accelerating a lot. I suggested that as the Caravan tends toward being spin resistant anyway, holding it in for a turn just to prove it will come back out has more risk than benefit, when it's agree sufficient to show that it's really hard to get into a spin, and a prompt recovery gets it back out much more quickly, and with less speed and G that holding it in for a turn.
In addition to the stall in the video, I was required to demonstrate just about every other conceivable stall entry, so show recovery was benign and easy. I was reminded during this testing, and the video shows, that depending upon what you're doing (and probably shouldn't be in a Caravan), you can get yourself in a situation where both full nose up and full nose down elevator are being applied and momentarily held within second of each other. It's a weird feeling to be holding full nose down on a 4 1/2 ton plane!