YOur method sounds fine....albeit more work than you need to do. But if one valve is all the way down, adjusting the adjacent will be fine.... same cylinder of course.

The only advice I can offer would be to use two feeler guages. One that is .001 thicker than spec., the other .001 thinner. Adjust to where the thinner one fits, but the thicker one doesn't. Double check each one after tightening. That way you know damn well you got it right.

And yes.... if I were you, I'd check them again in a week or so. They probably won't change, but if you think they ain't right...best to get back in there and re-adjust soon.