No I edit the svg file from Inkscape and remove them from all the font related entries for example this one from a schematic svg
style="font-size:48.61109924px;font-family:'Droid Sans';text anchor:middle;fill:#000000;stroke:none"
Inkscape will reinsert that px every time it loads and saves the svg and after a parts edit or 2 Fritzing will set the fonts to 0 size. The fonts I'm using are from the Fritzing graphics temple at
http://fritzing.org/learning/tutorials/creating-custom-parts/download-fonts-and-templates/
The fonts are in the zip file and you run them to install them.
Peter Van Epp