[quote=Yog Sothoth]
According to the dragon ball wiki, Broly never has to power down and he keeps getting stronger as the fight goes on.so legendary super saiyan is a form that never burns out or at least it weakens at an extremely slow rate when compared to the other transformations
[/quote]

And given that info which is apparent

I'm sure Silver can figure out a way to dial that sort of thing down