Unencrypt does do a lot of un-necessary work in that every time it runs it scans the whole video folder to find files to convert. It converts the first one it finds then exits. You then have to run it again to do the next file, again scanning the whole video folder. It would be useful for it to have an option, say -a , that makes it keep going and allows it to convert all files that need converting. This would mean only one scan of the folders and the conversion process would be completed faster. If you wanted a limit on the number of files converted at a time, a max file count option could be added, say -mc5, that would stop it processing after 5 files or when all are done.
I turn it off when recording more than one stream just in case it degrades the recordings. I have not tested it to see if it does but the fact that it's default is to run over night I thought it would be prudent not to run when the Hummy is under load, recording 2 streams and watching a third.