Good enough is not a measurement or in my tool box, so no........there is not a "good enough" standard I will accept in my day to day work
Of course money is finite, so I am bound by the rules of how much things cost just like everyone..
But just a couple quick examples;
Fork oil- most would assume that if you fill the forks within say about 2mm of each other that is "good enough"----you would never find that with me.....they are exactly the same--or as close as my tools can possibly measure.....it is free to do it correctly, why wouldn't you
Valve clearances, many think within spec is "good enough"...good enough is when they are perfect, that is when they are good enough, even with standard shim sizes you can easily attain a clearance variance of less than .0005" between all 8 of the intakes or all 8 of the exhausts.....again, why wouldn't you do it properly?
Cylinder bore? Big end rod roundness? etc........those can easily be made to be perfectly round (they don't come that way from the factory, and only get worse with use).......if you are in doing the work, why not make them perfect?--there is no good enough when it is so easy to do it right.
Throttle body sync/Carb sync.... again- easy to be perfect, so what the fuck is "good enough".... it is perfect, nothing else matters
Wheel alignment, chain free play, tire balance etc..........all the same deal.. Why be "good enough" when perfect is easily achievable.
The answer is LAZY !