How have I been dragged into this conversation? :)
All I will say is most skinners do not care if a user sets the font to a plus percentage.
We design our skins based on default font size as defined in the skin files.
This allows us to correctly work out the layout of all the elements. You do not oversize and overlap elements just in case someone decides they want to increase the font size.
I even suggest in all my skin 'recommended settings' that people reset all font sizes back to 0 to ensure the layout is how the skinner designed it.
To be honest I think that option to increase font size is just legacy and serves no purpose in modern skins and modern 40+ size TVs . I wish image builders would actually remove that font size option. it is the devil.
It was only ever an issue on very small screens or some european skins that try and have a million things going on in each screen.
Estuary is not an overcrowded skin. Its fonts are sized to be perfectly readible.. Why do you even need to increase font sizes.