Tuning calibration heights by printing calibration objects

[saffi]

I'm not the best at measuring consistently, especially the heights during the G30 routines. My back to back measurements on the same probe point can vary 0.05 to 0.08mm and I've still been getting first layer inconsistency on items larger than 100mm or so in width or length. I went back to leaving all my H values at zero since they didn't vary by more than 0.03 on average.

If I print something like a 0.1mm layer height 130mm radius circle or similar delta calibration object, would it work if I made notes on the parts of the object that were not sticking well or too thin and then went back and modified my G30 values by 0.02mm at a time until I got a uniform calibration object?

Is this a sensical way of calibrating? From what I can tell, I'm not experiencing any concavity or convexity in my first layer, it's mostly just certain areas (like near the outer X-Y axis) that are too thin - meaning I'm moving too close at that particular point to the print surface.

Thanks for fielding all these questions btw!