It’s true that a more advanced bot would be helpful, surely. However, I am not convinced that there is not a more efficient solution. For instance, arbitrage between exchanges is very difficult to code in a bot, as many exchanges require something akin to email confirmation or 2FA in order to withdraw funds.
Basically, my argument boils down to that decentralization solves this issue. By offering tempting rates with limited target, an unfilled pool will attract providers such that the moment someone’s order is purchased someone else puts one in their place. This gives the custodians time to rebalance their own funds without Nu losing the peg.
On exchanges where there is a full hedging circle (NBT/fiat, NBT/BTC, BTC/fiat) a more advanced bot like you describe would surely be beneficial. However, there are just so many possibilities and parameters it could get quite complicated (and therefore expensive) to design a bot that fully meets your expectations.