This should be now fixed in KiCAD >6.0.1, so setting all visible is no longer necessary. One consequence of setting everything visible thought as a fix is that it also set dimension layers visible for example, so Populate would draw the SVG on the generated webpage to be the wrong size
As it turns out, the
ComputeBoundingBoxreturning zero was actually a bug in KiCAD, and the reply from https://gitlab.com/kicad/code/kicad/-/issues/9452 was a misintepretation/oversight. I did trace the bug eventually and reported it (https://gitlab.com/kicad/code/kicad/-/issues/10179).This should be now fixed in KiCAD >6.0.1, so setting all visible is no longer necessary. One consequence of setting everything visible thought as a fix is that it also set dimension layers visible for example, so
Populatewould draw the SVG on the generated webpage to be the wrong size