Irs2092 works at a voltage of about 14V DC.The issue is the heating of the 2092, that has no heatsink and blows up. The switchers themselves dont run very hot...
Whether the voltage of your main power supply is + - 70V or l15d + - 50V.
The irs2092s operates at 15V. It has a separate regulated power supply.
It will not be affected by the voltage of your power supply.
So it won't get hot.
The severe fever is irfb4227. And inductors. if possible. You can point a fan at them.
But it doesn't matter if there is no fan.