Hello,
I just tested the manual record and when I stopped it I went to Library , saw it was there but when I wanted to watch it VLC opened black screen, no video.
Then I checked the ressource usage on the machine and saw ffmeg was still working on video encoding (see my little resource meter showing ffmpeg using 50% CPU.
So may be you could add some flag to Library showing that video has been added to library but not yet available when backgrournd encoding setiing is active or may be the record item can be grayed the time ffmpag is working, not a big deal as manual record is something you do rarely.
regards.