Only one of the competitors I am aware of have integrated Kotlin. (If we can count CF as a competitor ^^)
Looks like this is more a "legal" issue or the fact that Kotlin is not a "fair" language.
The solution to the first potential problem is clearly out of reach for me as I lack proper documentation.
The solution to the second potential problem (PP) is easy : no ranking for Kotlin solutions and reduced XP.
Though, I wouldn't even "solve" the second PP since, after all, it is a tool available for everyone, for free!