I’ve tried to exchange files between Intaglio and Inkscape (whose native file format is SVG).
Export from Intaglio to SVG works mostly fine (I was happy to see that accented letters were not changed into hieroglyphs;-) except that:
all objects on one layer in Intaglio are grouped, once the file is opened with Inkscape. If there were groups on a layer, they become sub-groups in the resulting file.
there is only one layer in the resulting file, which contains all the above groups (1 group = 1 layer in the original file).
Import of an Inscape-created SVG file works much worse:
the objects are distorted (circles are turned into ellipses)
the page format (which was originally Portrait A4) is a weird 55 cm wide x 20 cm high. If I change it through Edit/Page Setup… to a Portrait A4, the page is now 39.5 cm x 27.5 cm (a little smaller than a Landscape A3), and all my objects still don’t fit in the page.
Inkscape claims to use SVG as its native file format but this is somewhat misleading. SVG by itself doesn’t contain enough information for a good default vector file format but allows for customization. Therefore Inkscape makes some custom additions to standard SVG. However these additions are Inkscape specific and go beyond what is defined for SVG. In a sense you could argue that Inkscape’s native files are compatible but SVG but Inkscape isn’t a universal SVG editor. Inkscape writes files as correct SVG but won’t necessarily read any SVG file and render it correctly.
I could be wrong but I don’t think the SVG specification defines layers. It might be the case that Inkscape marks layers as a special kind of group it can recognize again later. When Intaglio exports SVG it treats layers as groups. That’s what you’re seeing when you import to Inkscape.
I’m not sure about the page size issue. It may be that Inkscape is defining the page size and Intaglio is doing its best to accommodate that.
Can you send me a file that shows the problem of circles turning into ellipses?