i'm not an ajax programmer, and moreover, many people complaint about using javascript in the template.
i think in the future we'll have 2 templates, one plenty of javascript, and one with none.
at the moment i'm working on the server itself, not on the template.
there are other people who are working on the template in the specific forum.
in the while, you can edit the template and change this line to fit your needs:
<meta http-equiv="Refresh" content="3;URL=/~progress">
anyway you are right, 3 seconds it's a short time, good only in LAN.
it will be 7 seconds in 2.1 final.