The Grant module requires "Amount Requested" when entering a grant. This information may not be available when the grant is created. Why is this a required field? How can we make it optional? Workaround is to make it 0.
I don't think there is a non-coding way to do this. You could try to manipulate the UI with an extension to accept a submission without an amount value. But there may be reasons in the business logic why an amount is required, i.e. you may experience follow-up problems if there are grant records without that value in your database.
So unless this is a serious problem for you, I think your workaround is the best way to go.