0dte/2dte Double Diagonals SPY

Double diagonal on SPY, selling .35 delta 0dte shorts, buying $2 closer in strike 2dte longs. For example if SPY is $685, selling $688/$682 0dte, and buying $686/$684 2dte. The goal is to close the position when it reaches 20-25% profitability. Rinse and repeat several times throughout the day if possible. What hurts double calendars/diagonals is IV coming down, but using long legs with less time (2dte) there is less vega exposure. The shorts being further OTM than the longs ($2 difference) prevents gamma ramp up so aggressively in shorts, and longs only being 2dte makes them sensitive to gamma as well. There should be positive theta since the shorts and longs have difference in strikes and 0dte vs 2dte, which should allow positive theta burn. The distance in strikes allows intrinsic value to begin to rapidly build as once long goes ITM, creating delta expansion. This is a structure which offsets vega loss, prevents aggressive gamma ramp up in shorts, allows delta expansion in the longs, and creates positive theta expectancy. You want the price to go to ITM on one side and close before day ends.