For this corner shoot, I set my camera to manual mode to deal with the triangle setting; Aperture, Shutter Speed and ISO. First, I knew that I need the shutter speed in between 1/1000 to 1/2000 to freeze the actions or you could play with slow shutter speed and have the flash to freeze the actions as well. Since I wanted to test the HSS so slow shutter speed was not an option for me. Second, at a high speed carving corner with late evening lighting, autofocus is not my option. I would prefer to use manual focus with the depth of field to keep the riders in focus at my desired area. I was shooting with 2 lenses (Fujifilm XF14mm & XF-10-24mm) so f8 should do the job. Third, I dial up the ISO to my liking with the available light. One of the benefit of shooting mirrorless is that you can see the result instantly through the EVF. Lastly, I just need to adjust the flash power output from the V6II trigger to get the right exposure for the riders. Please note that do not tighten the V6II with the secure lever too far to the right side. There will not be enough space to lift up the ISO dial.
The photos below are taken by Fujifilm X-Pro 2 with Cactus RF60 flash & V6II remote trigger.