Adam - This is basically needing the ability to manually choose a custom profile that would have its own categories and custom whtelists and blacklists (just like Homework and Primary but it's own profile).
This would also solve my needs as well, per our recent discussion about a month ago, to set my children to their 'Primary' profile manually once they've shown me they have completed their homework (until time expires on the schedule for the day). Also, schedule ability to have these custom profiles enabled - like Primary and Homework except ability to choose on the time schedule chart the custom profile. A 'bedtime' custom profile would be great for Ketev to where he could block most everything and whitelist only Spotify or iTunes music etc.
I don't think this is that uncommon a need - however most haven't thought about this being possible - and it would really leverage the abilities of the Koala that are mostly already implemented.