My experience has been that people who learn both three-pointers and wheelers for their tail-wheel endorsement on a Decathlon (students of present company excepted) fail to master the wheeler or confuse the two techniques resulting in their passenger (me) getting very scared for safety of the aeroplane and occupants.
Some schools only teach three-pointers on the Decathlon (I have some old handling notes which have been around Moorabbin for many years stating that wheelers should not be done). After some solo experience it doesn't take long to get some dual and really master wheelers.
Of course, some-one doing the endorsement then moving onto another type definitely must do wheelers.
Otherwise, my opinion of Decathlon tail-wheel training is that if the individual is sticking with that type for the immediate future then the best plan is to master the three-pointer, get some experience on it then come back and master the wheeler. The aeroplane can easily handle crosswinds to the max recommended etc with the three-point technique.
Regardless, the new draft Part 61 MOS which may be dropped on us before 4th December gives us the required performance criteria to apply in future. For example:
Lands aeroplane in the following profiles:
o main wheels and tail wheel simultaneously (three-point landing)
o wheel landing (main wheels only on touchdown)
o flapless landing
....
Crosswind, headwind or tailwind to the limits of the aircraft type.
Sealed, gravel or grass runways.
Short landing.
Calculates landing performance in accordance with performance chart.
Stops aeroplane within calculated landing distance.
Good luck with that!