Multiserver or at least 2 server support.

[MaxL]

Idea is that i can set at least 2 servers with priority like with NL so that if 1st priority server cant find some article than leech engine goes and try leech that article on 2nd priority server ( or more servers but 2 is OK)
Another option is to really use 2 or more servers concurently (with as many connection i like).

[Rdl]

Added. Multiple primary and multiple backup servers. Also retry count and retry delay added. So when all backups were cheched and no atricle found, retry count increases and then after retry delay article will be again checked on primary and its backups. After retry count= defined retry count, that part will not be downloaded.