Yes, that is a potential workaround, just one that requires much additional time and effort, as I had already completed much of the return.
Given that it is not unusual to have to AMEND prior returns, which is the case here, it seems overly burdensome that TTB should lock the beg bal capital fields in this case. It is NOT consistent with its historical and current functionality of allowing *other* fields which TTB calculates to be overridden. Why lock these fields and not others?
