Do extension Inf's files, do they inherit the class that there attached to

Question - Do extension Inf's files, do they inherit the class that there attached to.

EX - if i have a USBVideo class, can i add values to the [USBVideo.HW.AddReg] section

So i was trying to extend a USB UVC camera with a INF extension file. I grabbed the example here and it got it to work. I added a friendly name to a existing camera.

Then i wanted to add these registers to my inf file but they didn't seem to take. This is what my extension inf file looked like. I also tried to add them to the [USBVideo] section like a different example suggested. All the new code i added didn't seem to add a register in the HKEY_LOCAL_MACHINE -> system-> currentCotnrolSet->Enum section of the device.

[Version]
Signature   = "$WINDOWS NT$"
Class       = Extension
ClassGuid   = {e2f84ce7-8efa-411c-aa69-97454ca4cb57}
Provider    = %CONTOSO%
ExtensionId = {zzzzzzzz-zzzz-zzzz-zzzz-zzzzzzzzzzzz} ; replace with your own GUID
DriverVer   = 05/28/2013,1.0.0.0
CatalogFile = delta.cat
PnpLockdown = 1

[Manufacturer]
%CONTOSO% = DeviceExtensions,NTamd64

[DeviceExtensions.NTamd64]
%Device.ExtensionDesc% = DeviceExtension_Install, PCI\VEN_XXXX&DEV_XXXX&SUBSYS_XXXXXXXX&REV_XXXX

[DeviceExtension_Install]
; No changes

[DeviceExtension_Install.HW]
AddReg = FriendlyName_AddReg
AddReg=USBVideo.HW.AddReg ; new code

[FriendlyName_AddReg]
HKR,,FriendlyName,, "New Device Friendly Name"

;;;;;;;;;;;;;;;;;;New code
HKR,, SensorCameraMode, 0x00010001,1      ; places the value under device HW
                                          ; Registry key

HKR,, SkipCameraEnumeration, 0x00010001,1 ; This makes the camera available
                                          ; only for application looking for
                                          ; IR cameras

; same file's as above just in a different section for testing purposes  
[USBVideo.HW.AddReg]
HKR,, SensorCameraMode, 0x00010001,1      ; places the value under device HW
                                          ; Registry key

HKR,, SkipCameraEnumeration, 0x00010001,1 ; This makes the camera available
                                          ; only for application looking for
                                          ; IR cameras

;;;;;;;;;;;;;;;;;;End of new code

[Strings]
CONTOSO              = "Contoso"
Device.ExtensionDesc = "Sample Device Extension"