Slowdown on non final chunk upload

[kubco2]

Hello,
I use upload control in presentation view of uploaded files and problem is that every nonfinal chunk of file generate page view.

As upload continue and files count increases, page loading increase too and then every nonfinal chunk generate whole page which can takes long time to generate(for me it was sometimes more than 10s to render page(a lot of files)).
Final chunk of file is fine because of sending only snippets.

If plupload is ajax based, it should send json based response, or no?
Or how can I properly detect nonfinal chunk POST to disable generating page view?

Thanks for response.