Tileset selection is something that I found confusing when I was new. There were two lists, and I wasn't quite sure what the difference was.
The names "FONT" and "GRAPHICS_FONT" make sense for a veteran player familiar with the init file, but for a new player, it is kind of confusing. Maybe these could be changed to something like "Text Tilesheet" and "Graphics Tilesheet"? I think those are similar enough to the init.txt file names that players familiar with the old names would understand them, and they'd be more clear for new players.
And unless using TWBT, only the tilesheet in one of these lists will have any effect for the player. Perhaps the other list could be grayed-out or even hidden when the Print Mode is not set to "TWBT". When TWBT is disabled, only the "GRAPHIS_FONT" is used when creature graphics are enabled, and only the "FONT" is used when creature graphics are disabled.
Also, graphics packs with TWBT-support often include tilesheets that are intended specifically for use as either the FONT or GRAPHICS_FONT. Maybe there could be some naming system or text file that graphics packs could use to cause them to sort to the top of the appropriate lists. The tilesheets that the graphics pack intends for use as "text tilesheets" would be displayed at the top of that list, and its tilesheets intended for use as "graphics tilesheets" would be displayed at the top of that list. Then after those, the Dwarf Fortress default tilesheets and the content from the /LNP/Tilesets/ folder would be displayed. And finally the tilesheets from the graphics packs that were not intended for use in that list could be displayed at the bottom – or maybe even optionally not displayed at all. Meph_32x32.png would never be usable as its text font, for example.
Example showing different content sorting to the top in the two lists: