Welp, I did not find the answer for this on entire Internet.

Yes, we have, like, "Smart episodes" filter, but it does not work when the torrent item comes different authors.

If the problem is not clear, I can describe it more:

The problem

Assume that I have one RSS feed from some sources where many people post torrents, maybe of the same content.
I have configured automatic RSS download by multiple filter.
If two versions of the program, e. g. "Program 4.6.2" and "Program 4.6.1" were posted, it will download both for RSS rule /Program\s\d+\.\d+\.\d+/i. Maybe the Program torrents were posted by different accounts for the given RSS feed so the "author" prop in RSS' XML is different.

All I want from qBittorrent is to delete the older version. How?