The whole process remains the same! Mind you, I just add an additional step at
the very end of the process: the conversion from relative to true! Whatever happens before that doesn't matter in this case!
Oh, and it doesn't matter if the sub moves at 1 knot or 10 during tracking! The data will always be relative! When you treat 1 knot as 0 knots, there will always be a error in the end result! So by doing the vector calculation for any speed above 0 kts should also increase the presicion! Another benefit.
Anyway, we can discuss this all day long and won't get anywhere if we don't try in in game.