Well done video and very informative. Filled in a couple of blanks. Always been a great fan of Robertson screws. Couldn't have done some of my boat building stuff without them. Reaching into an area, only possible to reach with one hand and getting the screw to stay on the driver.
In my younger days there was also a Philips, almost look alike, called a Reed and Prince, which could cause a bit, no pun intended, of grief when mixed up with a Philips.
Too bad history went the way it did. On a rating scale I'd rate the slot driver at the bottom and the Philips about 2/3 as good as the Robertson.