It all depends on your camera and its speed capability v F range of lens, so for instance a Nikon D500 can be set to iso 100 can do effectively iso 50 (low-1) so at F3.8 (round to 4) on the set up shown a bracket series ought to be able to capture C2 and at 10 fps I figure I shoot off 20-30 shots observing C2, and then the camera writes while I adjust iso to 640 for the corona, shoot a couple hundred bracket images, and if I am nimble enough go back to iso 100 at the end. The D500 will do 1/8000th so 10 fps fits the time well. Xavier Jubier's web site is indeed great for planning. That is the current plan for me, needs practice to see if it works. At 640 the exposures are in a great range for the corona - A lot of thought needs to go into planning those 1-2 minutes, no redo until 2019 (maybe) !
This set is from Svalbard ISO 800, F6.3 using a nikon F4 300 mm and 1.4X teleconverter (420 mm) on a stationary tripod , the Vixen set up will be a stop faster, and 570 mm equiv.)