When to put OE Tweaks during Unattend install ?

[fredfred]

I have try to make some OE tweaks using VBS and run during T-13, T-9 or after GUIrunonce

but OE said some user is in using and can't switch user when I start OE after complete installation.

I think the OE registry is not created completely since I have only apply changed entry.

so, when is the best timing to apply OE tweaks ? that can work ?

Thanks