You're right, you can leave it off. (which will also make it easier to pull the clutch lever!)
I've had many problems with the adjusting screws on the hand levers striping out, & just a little slack in the cable can cause the cable to fall off the engine lever...
I might actually try removing this spring for a few days to see if I like it better? (it does seem like a better way to go)
But yeah.. he needs to put that heat shield on!( you can see how his cable is melting)