Dan,
First you have not followed the sequence used by BEagle and many others when teaching SCA. Therefore, you lie somewhere between. However, as can be seen from the following diagram where I have accurately drawn your example a simple change in how you think of what your are doing will
1. Improve the accuracy; and
2. Show that the method has at least the potential to get you exactly back on track - provided the correct actions are taken.
On the left is your example drawn accurately;
A is the start point - B is the point where you apply the SCA.
C is the point 1 minute later where you decide the track error and apply that also.
D is where you are when you think that you are back on track.
Note that in your example [B]the SCA has not taken the aircraft back towards planned track (since B to C is paralleling the planned track). It is only through application of the wind correction that the aircraft starts closing with the planned track. How confusing is that to a student ( the standard closing angle does not close with anything)?
To the right is the exact same scenario using the sequence I am talking about;
A is the strat point - B is the point where the track error is corrected.
C is the point 1 minute later where the SCA is applied
for 4 minutes
D is where you are back on track - and had you done as I say you would be exacly back on track!!
SCA does dork very well if it is done properly.
Both examples would suffer equally because the leg back towards track is more into wind thus - your example would be more off track that shown and my method would be slightly off track.
The circles approximate the minimum visibility possible for VFR in class G. (they are 0.9nm radius which is a little generous!!)
I am not seeking to reinvent SCA or do something that you are not already doing.
You applied SCA then MDR (drift correction).
I am saying that MDR (drift correction) followed by SCA is more accurate, involved the same actions by the pilot (but in different order) and can in theory actually work whereas SCA first can never.
Looking at your righthand diagram. The reason why SCA works perfectly in that example is because the TMG is paralleling the planned track when SCA is applied - exactly what I am talking about.
I don't know why your friend flying in Australia does not know how far off track they are having avoided the weather. Had the used SCA to move the required number of nm right of track to clear the wx then (all being well), they would apply the same SCA to get back to track.
SCA sounds complex at first, but the beauty is that it's quick and easy to use once you have had a bit of practice at it - and it doesn't require a visual feature on track to fly to.
SCA is not complex. How easy is it to check the drift line, kill the drift and then SCA for the required number of minutes back to track. - Very.
Your "fly to a feature on track" system is indeed valid - provided that it is not repeated again and again. In other words - look out, see the mast, fly to the mast and when there fly the correct heading - the one that would have taken you to the mast with no error. To do that the pilot still has to be able to determine the drift and MDR the correct heading. Otherwise it is track crawling.
In sumary, I am not adding or removing anything from what you describe. I am merely changing the order of actions to make the resuly more accurate and the method valid as a "get you back on track" method.
Get the idea?