The font-sizes are relative in the dashboard (they don't seem to be defined anywhere in the styles), Would something like this be feasible ? Like a "base"-font size.
I have added the font-size to the styles manually and it appears to work (read override) for all elements.
Are you saying you have implemented that ? in which case a Pull Request would be welcome to look at. If just a mock up then - yes of course it is feasible but I suspect there are a lot of edge case / places where the font size is hardcoded and would need to be made relative sizes - not least in some of the widgets - that use 3rd part libraries - that would need a lot of work to iron out.