You will need to enter the product to trigger quotation determination. In another word, quotation is determination based on the item. You will need to implement your enhancement to search for quotation with same sold to party and create docflow for the found quotations. But in this case, I am not sure whether item change in your final quotation will or not update item in the individual quotations. The standard function will update preceding quotation's item status if item quantity in the followup sales order is met.
Spencer