I can see in my uedit32.ini following:
[Full Screen TB]
But after some tests with UE v14.20 Beta 2 and a search in uedit32.exe for "Full Screen TB" I know now that this INI setting is not used anymore. I don't know why it was removed, maybe it was a mistake. I will report this to IDM support by email.
By the way: While searching in uedit32.exe for full screen settings I found an undocumented INI setting
Force Full Screen=0
If this setting is set to 1, UltraEdit will start by default always in full screen mode. This setting can be only added or changed directly in the INI. I don't know exactly which version was the first one which supported this setting. I searched in my archives for the ASCII string "Force Full Screen" in uedit32.exe and found it in the EXE of v11.10c and later, but not in v10.20d and previous.
Update: The problem with remembering and restoring the position of the very small toolbar with the symbol to turn off full screen mode was fixed in UE v15.00. The position is stored in uedit32.ini under [Settings] with FullScrButton=