All XieChang controller boards are designed for no more than 72 volts nominal.
They can handle maybe 100 volts max before the need to "protect" the R10 and R11 resistors from overheating.
In addition, the components of the switching circuit are themselves rated at about 100-120 volts max.
Specifically, the standard SS110 schottky diode (D8) is rated at 100 volts max.
The tiny switching transistors (Q13, Q17 and Q18) are rated at maybe 120 volts max.
Finally, the five tiny resistors (R116 thru R120) are subject to burnout due to initial "turn-on" current surge.
I've posted a simple "high voltage" solution to address all these issues.
The solution has been tested and works perfectly on my own controllers at and above 150 volts.
If this solution (or an alternate solution) is not used for 150 volt operation, it is predicted (and already proven)
that premature failure of these components will certainly occur.