The problem with being on or just over the max junction temp, is that the damage being inflicted is done over time. It's not always a lights-on/lights-off kind of thing. So it may take days, month, or even years for the devices to finally break down. Of course there is a temp that will, in fact, destroy them instantly. That is probably the melting point for the softest material in the die.
In any case, that is much too hot IMO. More channels, lower current, or better part power capacity is needed. Getting parts in a different package would be easy enough to do.