I’ve gotten some feedback— and help! 
— from @cculber2, @aronos & @matta on the Rollover Adjustment/Budget Offset concept and have implemented it in the hidden area. Documentation is still thin, but @cculber2 has done a great job writing up where we stand here.
Once we see that these calculations net out and are helpful across a diverse set of community budgets, we can figure out how to render them in the unhidden area of the Savings Budget.