Just an update on this issue:
Kickass is still very slow on updating seed information for newly added torrents (it can take up to 6 hours ).
It seems most releases are failing to be snatched on kickass now because of this.
Before it would occasionally fail (it would take around 10 mins for it to update seed info) which is within the 15 min default rss sync time, but releases are usually posted multiple times by different users so something was nearly always snatched.
I can see minimum seeders being very useful when doing an automatic search/manual search which is likely to have older torrents, but for rss sync showing the latest torrents a bit of leniency on the number of seeders may be useful?