With the Bloc Québécois proposal, a decision to that effect would have been required, because even if we were to call it a refundable tax credit, it is a benefit. It is money, it is not a tax credit, it does not reduce taxes. People who do not pay taxes will receive the benefit.
As for the way that provinces establish benefits based on income, the same type of agreement would have been required,as is required in the current situation. When it comes to taxes, that is different. Once again, provincial governments could have decided to tax these amounts.