Could you formalize the shotgun approach? Remember, the expected MEV has to be greater than the opportunity costs of all those priority fees, both for producer-validators and for external MEV bots.

Assuming the need for exactly one transaction before another transaction (best case MEV), a priority gas cost of p, and a MEV of m, then an upper bound for the number of transactions for the best shotgun EV (t) is naïvely given by

p*t<m*\frac{t}{t+1}

setting the cost to benefit. Solving for t, we get:

t<\frac{m}{p}-1

Therefore, any transaction with MEV less than twice the priority fee will never be shotgunned. A slippage of 0.5\% is standard and the priority fee is about \$2 right now. Therefore, under my system, any trade less than \$800 is not worth extracting the MEV of.

EDIT: It’s important to note that this is a lower bound. The above equation makes a few unrealistic assumptions in favor of the MEV extractor. The true minimum value is probably \gg\$800.