Code:
CAB: \Extended ROM\whatever.cab
CAB: \Extended ROM\whatever2.cab
You'll also need to set the autorun flag back on because it's turned off in the kitchen, that way everyone's carrier customizations don't run.
Code:
[HKEY_LOCAL_MACHINE\Comm]
"AutoRunCFG"="\\Windows\\Config.txt"
"AutoRun"="\\Windows\\autorun.exe"
;0 to run, 1 means it already ran
"AutoRunFlag"=dword:00000000
You can also just check "TierAutoinstall" in buildOS. That's an on-the-fly tool for the autorun config.txt.
The first time you boot you'll get a checklist of all cab files in Extended ROM, Storage Card, Storage Card\Boot and \Windows. Pick what you want and autorun will install them and soft-reset.