I don't think there is much difference if the kid joins at P.1 or P.4, sine they only admit those kids with good results in their talent search or the aptitude test. As far as I know, most of the kids admitted are within the top 5% in their own school.
However, the parents should spend some time in monitoring their kid's understandting about the topics taught after each lesson. Bearing in mind that it is an intensive course and the material is in English, the kid may not be able to fully understand all the concept taught in the one-hour lesson.
For promotion to the next grade, the kid much pass the end of grade test at 80% or above. So, it should not post any difficulty to those continuing students.[/quote]