This image perfectly illustrates the issue. The infill/solid lines are paired! Strange, but I have a theory.
There is a delay or miss-synchronization when all 3 axis are moving (X,Y, extruder). Some how this is clearly visible in 45deg infill. So, certainly Zmorph needs a coefficient to mitigate this, and for other printers might have this coefficient editable. It depends on printing speed as well, shell does not show this issue, only infills/solid layers.
The printout like this, does not build trust in Zmorph accuracy, which I know is quite good. And a bit disappointing too.