What is the logic behind using the conversion factor in determining the hedge ratio of deliverable bonds in 30Yr UST futures (WN contracts) throughout the trading life of the contract, but then having a 1:1 ratio in actual delivery of the bond to the long futures holder in physical delivery period and therefore leaving a tail?

Edit to clarify my question:

If the deliverable bonds are specified at the onset of the contract, and a conversion factor is determined to make the deliverable bonds an equivalent yield, why does the conversion factor not follow into the delivery period? It would seem that if the notional amount of bonds to be delivered should the inverse of the conversion factor for the bonds that are delivered; thus eliminating the requirement to trade the hedge tail at delivery.

What is the logic behind using the conversion factor in determining the hedge ratio of deliverable bonds in 30Yr UST futures (WN contracts) throughout the trading life of the contract, but then having a 1:1 ratio in actual delivery of the bond to the long futures holder in physical delivery period and therefore leaving a tail?

Edit to clarify my question:

If the deliverable bonds are specified at the onset of the contract, and a conversion factor is determined to make the deliverable bonds an equivalent yield, why does the conversion factor not follow into the delivery period? It would seem that if the notional amount of bonds to be delivered should be the inverse of the conversion factor for the bonds that are delivered; thus eliminating the requirement to trade the hedge tail at delivery. Why did the exchange specify the 1:1 ratio for delivery, rather the inverse of the conversion factor into the contract?

What is the logic behind using the conversion factor in determining the hedge ratio of deliverable bonds in 30Yr UST futures (WN contracts) throughout the trading life of the contract, but then having a 1:1 ratio in actual delivery of the bond to the long futures holder in physical delivery period and therefore leaving a tail?

What is the logic behind using the conversion factor in determining the hedge ratio of deliverable bonds in 30Yr UST futures (WN contracts) throughout the trading life of the contract, but then having a 1:1 ratio in actual delivery of the bond to the long futures holder in physical delivery period and therefore leaving a tail?

Edit to clarify my question:

If the deliverable bonds are specified at the onset of the contract, and a conversion factor is determined to make the deliverable bonds an equivalent yield, why does the conversion factor not follow into the delivery period? It would seem that if the notional amount of bonds to be delivered should the inverse of the conversion factor for the bonds that are delivered; thus eliminating the requirement to trade the hedge tail at delivery.