Improve the Revenue mgt feature
The revenue module, with the payments schedule opens great perspective for managing forecast, or even tracking the performance of some pipes.
Managing negative amounts seems possible at first sight (and welcome), but can't be saved (=> Error). This would dramatically enrich the feature, whether you link it to actual billing, or another tracking purpose. For exemple I would like tu use it for inventory tracking, as some of my sales team, contract and manage Inventory capacities.
The standard design does not seem very from making it possible. It would be a small, but smart improvement.