OpenEuphoria

this is a great question, there is hardly any support in any of the toolkits to respect the user theme on colors, font, font size, positioning. in addition to font size, the DPI setting can be changed. not sure if this is what is changed in win7 Appearance.

so many programs I use have cut off text in status bars and dialogs because I have a higher DPI setting. even the programs like PSPad that now say they respect the DPI still have text too wide or too narrow but at least in PSPad it's not clipped off at the top of each character. other programs go extreme in the other direction with insanely tiny text and menu because they over compensate.

the internet browsers get it all wrong. complicated by CSS on each page wanting to set their own forced theme. there are some options and extensions to force minimum and maximum font sizes that just barely make things readable.

a test on as many systems as possible is still the best option, I always like programs more when they have a font size option, even better if they let you set font for other areas like menu and status dialogs. punt to the user at least recognizes that there could be preferences. newer toolkits make it easy to put a plus/minus font anywhere you would want them. probably an age/eye strain component. larger monitor, younger eyes don't really get the problem.