With the recent addition of "_thumb" for walls thanks to Paul, it is up for consideration what wall format the default art should use.
Default: this is the format that FRUA users are familiar with. The preview in the wall editor looks good. Small files size, but rather limited.
Hyper: this format was created by Dinonykos and has been around DC for a number of years now. Allows second and third story walls, better overlays and many more options. Large file size and doesn't look very good in the wall editor.
Hyper with thumbnails: the best of both worlds. The walls would be hyper walls and the thumbnails are in default wall format. Lots of extra files, though it should be obvious at a glance what is what. :Largest file size and looks good in editor.
Please comment on what you want, and what you think would work for someone new to Dungeon Craft (who may or may not know about FRUA).