Oz pointed out the little “curlies” (loops) to me when I had mentioned boxes.py to someone in another thread some time ago. They are an artifact of the “burn correction/allowance” and, as you’ve noted, are so small that they can usually be ignored. Since then, I’ve simply set the burn correction to 0 (no “curlies”) and used LB’s kerf offset to adjust the fit.
I pursued it a bit at the time, however – the “curlies” bothered me just being there – and found that if you import a SVG that has them… select all the shapes and use LB’s “Offset Shapes” by some tiny amount (just so the shapes don’t connect to each other… 0.1mm works for me) “Outward” and “Corner” and then delete the original objects. Select all shapes again and use “Offset Shapes” to move back “Inward” by the same tiny amount as before and the weird loops are gone.