Hey DutchRoll
What is the difference in fuel burn for DP and OEI DP for an A330. I know there's not a big difference on the T7. So at the end of a diversion out might not have a lot more fuel.
I know a lot of EDTO is a fuel planning exercise but if you are EDTO fuel critical and you're below flight plan fuel I think it's just airmanship to consider your options and make contingency plans, just part of being situationally aware.