Yes too tiny fonts are a pain! My own minimum size is permanently at 14 with font Verdana, works quite well. No idea why the KM-default is zero, or what this could be good for??
Because 0 means default font size, or in other words, 1em, and more to earth words, 12pt or 16px.
But 1em is different for each font. Verdana, in fact, has an em higher than other fonts, that is the reason it loo