Oh - I misunderstood what you were saying @Nige_S.
In this particular case, to a KM user the subroutine is a black box that takes inputs and produces an output so the actual implementation is hidden and - to the user - more or less uninteresting as long as it does what is expected. You’ve shown the advantage of avoiding the AppleScript implementation so if the user wants better performance the native KM would seem to be the one to choose. To be honest, given the choice I’d always use your version 
BTW - I love the way you ensure the delimiter is unique although I’m not sure of the benefit of displaying it!