Timing 3seconds per 100' Agl +\- wind
I reckon this is nonense and have done for years. What does it matter how high you are going abeam the threshold? The critical issue is going Downwind the correct distance so you will roll out of final by 400ft (or higher if you have to be stable higher up). By all means start descending passing abeam but the turn must occur at the same point over the ground. Headwind/tailwind on Downind? Adjust turn point by 1/2 second per knot of H/T.