Even if you have big space on your harddrive, you still sometimes notices that your space is low due to different reasons.
When you are in recording mode you can't do anything about it except checking auto delete.
But if there were a checkbox before every 1-8 input drop down list on/off, you could if low diskspace is near, just block a input or two, not needed for the moment.
I know I can lower the quality, but this would be a good alternative.