had it in my refugium last time until my chaetos outgrew it, thus it eventually melted. ( it was just a small bunch)
i would recommend you to give it more wave/light according to its size/length, if its a large bunch and theres insufficient wave/light, i believe the rotting from the interior upwards can crash a tank due to some toxic substance it holds.
not sure about the sexual or asexual part but they are a form of algae. i do know if you cant keep them in check at where it is now(enough light), they will break loose(this is due to the bottom rotting off) and grow at places with stronger light and flow.