Can the Budgetary Control perform retrospective evaluation of budget against actual spend?

Summary:

Can the Budgetary Control perform retrospective evaluation of budget against actual spend?

Content (please ensure you mask any confidential information):

We are in a new implementation and have enabled budgetary control. We are about to embark on live transaction entry but now understand that our final budget values which required to be loaded into the application for our control budget will be available only in couple of months time. Can we start creating our transactions and input the budget values for our control budget later, and will the application able to retrospectively automatically determine our commitment/obligation and the resulting balances please? We have no room to wait till we load the budget values to our control budget to start creating