Thanks for the suggestion.
I wish it was newton rings, I could solve it.
But those artefacts have a chevron-patterned aspect and can be observed on a light table.
I tested different channels combinations (same ink dilution in each), and it really looks like cutting down LC and LM (and rising other channels) makes great improvements, campaigning for a sort of conflict between X and LX channels if used equally.
This might not sound that much related to QTR, but I remember a discussion where it was stated that QTR uses its own dithering algorithms and that every channel has its own dithering placement of drops, contradicting a moiré possibility.
I hoped to get a deeper understanding of eventual dithering patterns interactions.
Moving on anyway…
Stefan Christiansen