I've also submit a bug report about this different size icons problem for the toolbars between system (windows vs linux): n° [1568475] Please, take a look and tell me what do you think.
OK. I've reviewed that and... "not a bug"
The effects you are seeing are exactly as intended. Inkscape is generating icons the size requested by the current theme. Use a different theme, get a different size. "Large Print" is one theme that is very good for exercising this.
Mmmmmh, I can't find the Print Large theme you talking about. I have only have: David_icons.svg, icons.svg and legacy_icons.svg Where is "the size resquested" you are talking about? In the .svg file?
On Ubuntu, Inkscape show the toolbar icons at 22x22 instead of 16x16 (some icons of the current theme was not mean to be showed at 22x22...). So what's the deal between windows and ubuntu version of inkscape ?