Using the DEX price for the feed creates a feedback loop, which is inherently dangerous.
The real source of the problem is that the markets are skewed, and arbitrage is difficult because of political boundaries. The consequence is that there is no single "correct" price. We've had that discussion before.
IMO under these circumstances it is OK to increase the settlement offset, and perhaps also accept a higher premium by increasing MSSR. The resulting spread could cover the market differences and protect both sides.
increasing MSSR is not a good idea.
I have a idea below maybe solve some problems.
Feed price= (CEX price+DEX price)/2, maybe clear, set two weight parameters X, Y, and one parameter Z like MSSR, these can be adjusted by committee:
if CEX price<= (X*CEX price+Y*DEX price)/2<= CEX price*Z,
then feed price=(X*CEX price+Y*DEX price)/2
if (X*CEX price+Y*DEX price)/2 >CEX price*Z,
then feed price=CEX price*Z
if (X*CEX price+Y*DEX price)/2<CEX price
then feed price=CEX price