With UltraEdit v23.00 the GUI changed by using the same Microsoft library as used by Microsoft Office 2007 and later Office versions. This step introduced the ribbon mode as the vast majority of UltraEdit users wanted according to the survey 3 years ago, but IDM Computer Solutions, Inc. added additionally also the toolbar/menu mode with contemporary menus and later (v23.20) the traditional menus for users like me which really don't like the ribbon interface.

The disadvantage of using the Windows Ribbon Framework in comparison to Microsoft's GDI library used up to UE v14.20 or Microsoft's GDI+ library used in UE v15.00 to v22.20: The font is hard-coded in the library. The library just applies the font size to menus and items on a ribbon tab, but not the font itself which is always Segoe UI (with a fallback to Tahoma if that font is not available).

Microsoft published the support articles:

1. Font of Ribbon in Office is hardcoded
2. Ribbon font in Office 2007 and Office 2010 applications cannot be changed

I don't know if newer versions of Microsoft Office support in the meantime a change of the font which could mean the library supports it, too.

I think, the developers of UltraEdit can't do anything regarding used font if the Microsoft library still contains the font hard-coded inside.

I have one computer with Office 2007 and another one with Office 2010. On both computers the change of font and font size in appearance settings for the menu just resulted in applying the font size change, but not in a change of the font. The menu font size of UltraEdit also changed like in Office after a restart of UltraEdit, but not the font like in MS Office.