I have played in a tournament where we had 2 order dice of another color added to the dice bag and when both dice were drawn the round ends no matter how many activations are left.
we have had crazy short turns to long turns where we almost drew every dice. The shortest turn was like 6 dice drawn until we drew both. I will say for a competitive environment this made it extremely hard on some missions and scenarios because you literally had to rush early to objectives and hope the turn ended early.
I didn’t like the mechanic myself because it definitely managed and averaged to cut turns shorter than usual making games too quick and didn’t feel like a game of bolt action.