I basically just tightened them enough to take out the slack plus a couple of turns. I bought the whole kit with bolts from Scamp
partially to see what length of bolt they used - I assume it's no longer than necessary, so there shouldn't be a lot of threads past the end of the self-locking nut. The only purpose of the spring and bolt is to keep the door from falling off, such as over bumps, excessive tension will just accelerate wear, and closing the spring up solid will keep the hinge from being able to accommodate hinge misalignment as intended (or as you said, Neil, useless).
I lubricate mine, because it seems to me that brass on aluminum needs grease
. My bottom hinge lube dried out, and the door started to stick and creak, and the drag was obvious as the forces cause the body in the hinge mounting area to flex.