The type QWORD in the registry element is necessary, because otherwise you can not set the ExecTime in a logon/logoff script call.
The type 'binary' or 'integer' does not work - the batch is not called.
Try is out with this test.reg entry
--cut--cut--cut--cut--cut--cut--cut
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\System\Scripts\Logoff\0\0]
"Script"="C:\Mybatch.bat"
"Parameters"=""
"ExecTime"=hex(b):00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
Logged In: YES
user_id=26581
Originator: NO
Windows Installer doesn't support QWord registry values.