How to seed many torrents through a slow connection?

[hrkr]

I have a slow ADSL line (tested 100kB/s down, 10kB/s up, no ISP throttling) and over 2600 finished torrents. Quite a few of them have no other seeder. I use uTorrent 3.0 beta with default settings (it behaves the same for 2.x).

I tried to switch into "seed-only mode" - disabled all downloads and enabled all the seeds. After a few seconds the down-speed stabilises to ~12kB/s (I guess this is tracker connection overhead) and up-speed to ~10kB/s - these are the numbers shown in top bar. Number of seeds grows slowly and steadily and can get to hundreds or thousands within few hours.

However, either none or just a few seeds do appear among the active and when they do, more often than not their "Up speed" column is empty. When I am fourtunate I see 100-400 B/s here. So it looks to me these ~10kB/s up is mostly taken by the overhead as well and I fail to do the actual seeding.

Does anyone know how to configure uTorrent to reduce the overhead or to cycle periodically through the seeds? Is there some other torrent manager optimised for heavy seeding through slow channel?