Proof of burn means sending coins to a not spendable address, right? So they are really burnt.
So if devs accept this way Pawncoins in order to sell ePawncoins, how can they sell the Pawncoins on their exchange for BTC and put a buy order with the BTC for the ePawncoin?
Pawncoins will not be spendalble, burnt, right? So how can they be sold?
They can be sold back, did you watched XCP. It has no volume because all those bitcoins are gone. Imagine having that back on the market.