Your fuel burn will be higher when you need to have 30 to 40% thrust to taxi. WAI is about 22%. Short runways normally aren’t that far away and otherwise you take an extra 100KG extra with you. I turn off WAI on the TO roll so it won’t matter, you have used that amount of fuel and is not a restriction for the TO calculations.
I agree that a fix should have been there already with the last update. I don’t even understand why we always have to wait until a published update. When the fix is there make an interim update, every developer is doing that except for Asobo.