A beter solution for transitioning between kitchens is to give all of your "portable" OEMs a unique foldername. Prefix them with "X_" or even "Custom_". BuildOS doesn't care what the folder is named so if you title them all with a single prefix at least they will all be grouped together.
Ideally BuildOS would allow for a "Custom" folder at the root of the kitchen where you could place your own personal OEMs and just tote that folder from kitchen to kitchen, but it's hard coded to only look in SYS and OEM so we just have to settle for "next best" until bepe or someone else invents a better mouse trap.
@gguru - as for your specific issues I was unable to confirm either one? The File Dialog changer in the kitchen doesn't have an rgu file (just looked again) and it built and works just fine for me.
And there is just one provxml file in the Telus carrier OEM (I should know--I made it
) and I just attribbed and it is not marked as a System file. Is it possible you were talking about something else or maybe it happened after you extracted the kitchen? Anyway please clarify.
I am not aware of any buildos-type app for an extrom. It would be sort of difficult to pull off automated program installs there because the main ROM still needs the reg entries and/or shortcuts. It is possible to create a flashable extended rom rom image though--lots of ROM releases on xda-dev offer them.