that cryptopia response seems to be fair. I have seen similar things happen to other coins, they did not take enough time and care about their major exchanges and got delisted because of too many and hasty changes in the algo.

This is a perspective that would require for SUMO to be more predictable with less hasty and rapid changes. Thinking along this line for a moment, what is the technical reason to move away from CN-heavy? I suppose nothing solid and logical.

More along this line, how about carefully preparing the rebranding and/or algo change to happen at the same time and make sure that you have all the relevant exchanges on board???

I think going back to CN will really impact credibility and trust. Two important soft factors, it is very easy to loose credibility/trust and extremely hard to regain!