Go into your torrent client like qbittorrent settings and you can enter unwanted extensions, *.scr, *.exe, etc. Same if you use a usenet downloader like sabnzbd or nzbget. Then if sonarr or radarr attempt to download an unwanted extension your torrent downloader will not download it.

Slskd

It uses the soulseek servers. Can run your own instance in a docker container. I listen to metal daily and you can find anything from other soulseek users.