Hi Fabian.K. :)
We all know that download manager like Free Download Manager, Internet Download Manager open more than 1 connection when downloading, so I think we can take some idea from them to improve our download speed, a feature that like speed limit, but allow Privoxy open more than 1 connection when downloading content, mainly aims to video/music file which really boost user experience when listening to broadcast, video sharing website like Youtube. It work like:
{+speed-accelerate}
/.*?\.mp4
I think it is possible and great if we have feature like this.
Seem Firefox have an addon that can do something like that: https://github.com/PRIVOXY-FORCE/rumal/Download-Unlimited/blob/master/Download-Unlimited/chrome/content/overlay.js
https://github.com/rumal/Download-Unlimited
Related to "Range:" request header.
But better if we can have our own way improve video/music download speed.
Thanks for the suggestion but implementing this would require extensive changes and I don't think it woudl be worth it.