Cleaning up while permaseeding

So my internet speed is not great but I have the storage space to permanently seed what I download. This works great for the most part and BP systems keep everything working well for me. However, over time many torrents will produce an error, either at the end of a season when the complete season is uploaded or a more generic "Unregistered Torrent"/"Torrent is not registered with this tracker". I want to keep anything that could be useful but I'm not sure if I should bother creating a script torrents based on specific error strings? I'm using Transmission which tends to be lightweight and manages a large collection well but I don't know if the old torrents might cause issues in the future.