Can be used with https://github.com/Kranex/goskew

Slice first model so that diagonal is largest possible to be measured precisely.

Mark printer's axis and coordinate origin on printed tabs before removing print from printer.

The diagonal from coordinate origin is A; the other (perpendicular) diagonal is B:

XY value for goskew is calculated as follows: XY = tan( atan( A/B )*2 - π/2 )

Use this correction and slice second model; minimal wall layers/infill may be used; just needs a stable rigid output. Second model is for XZ and YZ corrections in same manner.