It happens to me as well, for a while I just thought That I was really strong, so I backed off on the torque, but then it started shifting the hub in the dropouts on big hills or hard takeoffs.

We are just lucky that its the nut and not usualy the axle(knock on wood). I grab every junk SA three speed I can for parts, so thats how I deal with it. carry a spare.

And on patching a flat with out dismounting the wheel, its a pain if your fenders are close. I never can find the hole without taking the whole tube out. But thats usualy how I do it.