NoSkylightUpdates - fr1kin/ForgeHax GitHub Wiki
Render > NoSkylightUpdates disables skylight updates from being computed. Prevents framerate stutter in special cases.
If there's a huge object obstructing the light passing from the sky, a block update causing the light to flow/block will stutter the framerate as the skylight update will need to be processed. Taxing on the CPU.
.noskylightupdates enabled <0/1>