I'm not sold on the T20 witnesses operating this way being an effective way to deliver a responsive, and yet decentralised price feed. Understandably, the purpose of Luna is entirely stablecoins (which is ironically being undermined more and more by it's BTC holdings) and so our considerations are a little more complicated than just being ultra responsive. Perhaps if we had a greater number of participants, and several orders magnitude more participants / liquidity, then the 3.5 days can be reduced a bit.
In the same way that missing blocks has financial consequences, price feed updates probably should too. It is obviously a critical component of everything that is being discussed here, and currently gives no leeway to shorter conversion times for the simple argument that some witnesses update too infrequently. I'm not talking by the minute, or by the block updates.. something like every 8 hours minimum so that we can have 3 periods within a day to form the 3 moving average.
I feel like the price feed has not been discussed enough around here neither the rules around it. As it is now it is completely arbitrary. Any witness can set whatever price he wants at whatever timeframe. I feel like at least there should be some timeframe defined for witnesses to follow.