If you aren’t using FritzingCheckPart.py, there is one other important Inkscape gotcha to avoid. Inkscape (to be CSS compliant) puts a trailing px on font-size i.e.
font-size="49px"
Fritzing (I think mostly parts editor) will react to the px by either setting the font-size to 0 (and the text disappears) or a large value (and the text is huge.) FritzingCheckPart.py removes the px from the font-size (among other things) so if you aren’t using it, after editing an svg with Inkscape you need to either use a text editor to remove the px from the font-size or have a script which will do so.
Peter