Doubling the track error at the half way point will converge you onto your final destination, not the 3/4 point. (assuming you had flown a constant compass heading since start of nav).
The only problem with these techniques is that assumption of precise compass heading from your last overhead fix. Account for DI drift, less than accurate track keeping etc etc, then the calculations become more complicated.
There are many schools of thought on this. If you're not sure of the cause of the track error, then get back on track using standard closing angle, re-establish an overhead fix and treat that as a new start of navigation.
If you're sure that the track error is due to wind variation from your plan, then your method is as good as any.