Well, broadly speaking I think Beeminder could be a lot more powerful if it knew additional information about goals. I elaborate on some of that here: On making Beeminder more appealing to a wider audience .
For example, if Beeminder knew your daily maximum for a goal was 4h per day then it would know that if you’re setting yourself up to need to do 8h on Tuesday it needs to force you to do extra on the days leading up to that in order to span the Wednesday gap.