Sorry, I haven't had time to watch the video yet, so please forgive me if you answered this in the video.
The switches seem to me to be very fragile - it doesn't take much to break the little rivets or whatever that hold them together. This happened to one of mine, and I ended up with a little pile of parts. I eventually replaced the switch with a new (to me) one.
If you wanted to linearise the switches (which I don't), can you actually put the switches back together?