Riverhead says it's possible for exchanges to issue an BTS IOU...
It's possible, but not practical. Each exchange would have to buy a massive stake in BTS just to do this; to fund their IOUs which they have to convert from user's bitcoin deposits. This is a huge undertaking for them and a big risk; IMO, they just won't do it.
What the hell are you talking about? Why would they have to do anything different than what they are ALREADY doing to enable their users to trade POLONIEX.BTS IOU tokens? As @Riverhead already pointed out, the only thing Poloniex would have to do is remove BTS from their withdrawal page, leaving BitUSD/BitCNY (and perhaps BTC if we get a sidechain going) as the only options to get funds onto the DEX from Poloniex.
This was my first reaction but read the OP again, there can't be transfers to accounts, they can only be traded on orderbooks. People would have no guarantee to get their bts back if Polo used them for that. Meaning they would need to take it out first. Then Polo would have no BTS unless they bought them themselves.
I'm not sure what you're trying to say. It's a given that BTS cannot be transferred in the OP scenario. But user
will still be able to transfer BTC to Poloniex and trade a POLO.BTS token. They'll also still be able to move funds from Poloniex to the DEX by buying BitUSD (or BitCNY) and then transfering THAT to the DEX. Sure, it would be less practical for users, but that just means fewer people moving funds to the DEX. And from Poloniex's standpoint there would be NO CHANGE, other than disabling BTS transfers on their withdrawal page.
So can we put this issue to bed already? We can't prevent external trading of an asset on Poloniex (or others). A new chain would have the same problem. As long as the exchange can buy/sell the asset somewhere, they can let their users trade IOUs on their exchange. And they wouldn't need to hold any more of the asset than they do currently.
In any event, disabling core token transfers will be pointless until
enough people have
enough reasons to trade on the DEX. Also think about this. Currently no one is trading BTS on the DEX, and it's a
top 10 cryptocurrency. So tell me, if BTS is forked to xShares, who on earth is going to trade shares of an unknown DAC on an unknown DEX? Let alone the fact that most people don't even know what the hell a DAC and a DEX are to begin with. So the point is, a new chain doesn't solve any problems. In fact, it just gives us an additional set of problems, not to mention dividing resources and focus. And it will scare some of us away. You think intraday .00000401 on Jan 7th was painful? That would look like a picnic by comparison.
We should really get focused here. Let's do what we can to improve liquidity of bitAssets, with primary focus on BitUSD and secondary focus on BitCNY (for now). At the same time, let's explore the BTC sidechain idea, and continue to make it more attractive to trade on the DEX.
By the way, as trading on the DEX starts to pick up, perhaps we can start increasing the cost of transferring BTS so it becomes cheaper and cheaper to transfer via BitUSD/CNY vs. BTS. This way we can essentially ease into approximating the disabling of BTS transfers and see how it goes.