Nice work. I think it’s valuable to have a feel for what’s happening under the hood, and I wish GF would just tell us some of this information. Dan did mention they detect the Illustrator “Save As” comment once, which cleared up some of the confusion I had around why they were recommending it. The other issue I’m aware of is that Export had a tendency to create files with questionable Lovecraftian geometry (e.g. zero-radius arcs) that crashed the GF renderer and unleashed ancient horrors upon the land. Newer versions appear to lack this feature.
This is not entirely accurate. You can choose to export the artboard(s) or just the objects on it. I’m not near a computer now so I don’t have the exact names of the options in front of me, but’s something like All vs Document in the export dialog. If I remember correctly, there’s also a “use artboards” checkbox somewhere, perhaps in Save As, that affects the results. There are so many different options in this programs, it’s not surprising that people are seeing different behavior.
Personally I’m ok with Export because I don’t usually want to have my SVG files positioned on an artboard. I load them into the GFUI and position them visually based on whatever bits of material I have available. But there’s at least the option for special occasions.
Also, regarding the 20x12/5:3 situation: I was playing with this the other day because someone mentioned the software EazyDraw. I discovered that it is very picky about triggering the workaround. I have another post on the forum with an example SVG that does it. In this case, I had to edit the file to set the width and height attributes to “100%”, and then it suddenly snapped to 20x12. So I think this is less of a general-purpose feature than a workaround for Affinity Designer.