Use order date for order pricing flag in BPA controls

Need below confirmations on the field Name "Use order date for order pricing" in the Blanket Purchase Agreement.

1. Is there a way to default this flag checked in BPA?
2. Is this feature/field applicable to the agreement lines with Price Breaks only OR without price breaks as well?
3. Is this feature also applicable for the “Cumulative” price break type or only for the “Non-Cumulative” price break type?
4. For the agreement line without price breaks, we will use the price from the agreement line. So, if there is a price change on the agreement line, the new price will default to the Requisition sourced from a blanket purchase agreement, right?