A simple closed system, I like it.
It should be open source to allow community members to build upon. For example if it's chained (replace 'Reward share of Alice' or 'Reward share of Bob' with another 'ALBO' or shared account) the possibilities are limitless.
Yes this will be opensourced. If I get a solution it will be updated on https://github.com/steem-projects/rewards-split
As you mention this can be further nested and the limits are endless. Lets hope that this will also drive more intuitive UI for Award splitting, shared accounts that is inbuilt in blockchain.