Actually after playing around running file comparision software on registry files before and after removing the language i found out how to do it: Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Keyboard Layout\Preload]"1"="00000809""2"=-1,2,3 etc are the languages, 1 being the primary. This needs to be called at the GUIRunOnce stage. I tried it at the cmdlines.txt stage but it diddnt seem to work. 1 was already 00000809 but it cant hurt to make sure the primary language is the one you want there. Then remove number 2 (US english in this case). Of course they're not actually removed like they would be with nLite, but they're not installed. They're not usable and dont appear in language settings (and removing the extras stops that **** language bar showing too.)