script: Preview Window open and close

[Bandu]

a script that makes previews after sims. Right now if I run multiple previews for multiple containers over script, the PW windows stay open and network traffic accumulates this way

let say 3 FFX in the scene, preview for the first is fine, preview for the second loads both caches, first and second as PW from first is not properly closed. And it gets worse with the third one and so on...
I've tried to hide containers or deselect them but it doesn't really help.

Thanks