Sometimes, the environments in vanilla Morrowind feature too many lights for OpenMW to handle gracefully. If you ever encounter lights that seem to blink on or off depending on where you're standing, this is probably the reason why. A limitation of gl_Lights is that only 8 lights can affect any give...
Sort of - according to Ola Olsson, the author of clustered shading, forward-plus is AMD's (confusing) term for Tiled Forward Shading. He suspects they would re-brand Clustered Forward Shading as Forward-Plus-Plus.
+1. I'd love to see these issues diagnosed. One day I hope for lighting fixes beyond even vanilla Morrowind, smoothing out all the annoying seams and popping that's so apparent with torches/light spells.
You should copy them from the shadows commit instead and see if that works, as those settings on the wiki are seriously out of date (for one thing, it's now "enable shadows" instead of simply "enabled").