Please consider this, that it is not sandbagging, but a problem of promoting others too soon.
There are distinct differences to the games played by the different belts. May I suggest the top instructors do a correct service to be patient and give their top students all the proper tools to embody the high standards of their art.
Kron has time to continue to perfect his art. He would struggle at the Black Belt level now, but on the course he is on in time he will shine there too. Why rush it? It is the correct way to build a consistant champion. Others that follow the same path will provide competition and there is where the standards are met and those individuals then raise the bar once again.
Dont aspire to get the belt, be the quality that belt requires!