Lines in patterns are an old bug that's been around for years. That's a distraction from my question.


Adobe Illustrator

HOW TO REMOVE WHITE LINES FROM PATTERNS IN ILLUSTRATOR
https://ebbandflowcc.com/remove-whit...from-patterns/


Inkscape

Seamless Patterns Have Fine Lines In Between Tiles

https://answers.launchpad.net/inkscape/+question/114823


The lines may be a bug or the quality of the base tile, but that's not what I'm asking here.