@prasimix

This time I increased R63 with one of 0.01 in series as you proposed. Full scale, after calibration, was 435 mA.

Next I did was 33 ohm parallel to R63, it reached 497 mA.

I then tried 12 ohm parallel, resulting in indeed 500mA, full range in 0.5 a range.

I also did R63 in series with 0.01 and a wire to R65, but that reaches 498 mA max.

It seems you can already see whether 500 mA will be reached, the last calibration step will have a higher current than the target of 480 mA. Am I right with this assumption?

When I parallel the trace from R63 to R65 with a piece of wire, the 480 mA calibration step gives 525 mA actual current, and 500 mA full scale is no problem.

As a last one I did R63 in series with a 0.01 - 0.03 parallel combination, followed by a wire to R65,

bypassing the trace. This gives for the R63 combination calculated resistance of 0.082 + 0.0075, so just below 0.09 ohm. Calibration current at target 480 is now 490 mA. And, of course, 500 mA full scale is OK.