Scripting

Personally, I'd be using the proven Wix toolset to generate the transform but, as a casual observation, your code doesn't seem to create the 'BulkLoaderInstaller_Files' feature...

Does the Registry table exist in your MSI?
Your code is working fine for me only if the Registry table is present in the source MSI.

Here is an example how to handle it for CustomAction table:

https://www.alkanesolutions.co.uk/blog/2014/10/30/powershell-windows-installer-msi-transforms-mst/

...
#use the TablePersist method to see if the CustomAction table exists
$tableExists =  $database2.GetType().InvokeMember(
	"TablePersistent",
	"GetProperty",
	$Null,
	$database2,
	"CustomAction"
)	

#If CustomAction table does not exist
if ([int]$tableExists -ne 1)
{
	#Create CustomAction table
	$query = "CREATE TABLE ``CustomAction`` ( ``Action`` CHAR(72) NOT NULL, ``Type`` SHORT NOT NULL, ``Source`` CHAR(64), ``Target`` LONGCHAR PRIMARY KEY ``Action``)"
	$View = $database2.GetType().InvokeMember(
		"OpenView",
		"InvokeMethod",
		$Null,
		$database2,
		($query)
	)
	$View.GetType().InvokeMember("Execute", "InvokeMethod", $Null, $View, $Null)		
	$View.GetType().InvokeMember("Close", "InvokeMethod", $Null, $View, $Null)
	[System.Runtime.Interopservices.Marshal]::ReleaseComObject($View) | Out-Null
}
...