I agree that aligning a transmigrated canine is very complicated but the mesialization of all posterior teeth is complicated too and you need skelettal anchorage to avoid negative side effects on the anterior teeth. So early detectection of migration and sound biomechanics to align the not so far migrated canine seem to be the key.
I think an important determinant of the treatment success is the position of the apex of the impacted canine. If the tooth is migrated from its origin position in the arch to a large distance then the treatment duration of morbidity will superced the expected outcome. A suitable alternative can be surgical autotransplantiion in the socket of decidious canine.