So, we know that Broly is a freak who couldn't control his own ki in LSS form. Even being stronger than 4 SS and a Super Namek, he was still defeated, twice.
What if he decides to train in hell, grows a brain and stops his ki from leaking out?
I assume that a 'Stable' Broly will be far stronger than Crazy wild broly. He will possibly go LSS2 and maybe 3 after enough training in otherworld.