Overheating issue with OpencoreLegacy and iMac late 2015/m395x

Hello,

I have a late iMac 2015 with an upgraded GPU of m395x, when running Opencore with Sequia the GPU runs pretty hot and when under large loads the machine just goes to sleep.

I can wake it back up again but generally have to close the app causing the problem and wait a few minutes, according the MacsFanControl the GPU is reaching 110 degrees during these times. According to the console the reason for sleep is -80, which aligns as this is an emergency sleep due to overheating GPU.

I don't have this problem when I run the stock OS, so it's not a hardware issue with the iMac.

Anything I can do?