From what I know, this mod(reshade rtgi), uses pixels brightness relative to the surroundings to draw indirect lights. It is possible that the textures you are using from the mod is not bright enough.
For example: http://www.framecompare.com/image-compare/screenshotcomparison/9JJ1MNNU
Not all blue screens have ambient light, only the brightest one does. I can only suggest put indirect light slider to the max in the RTGI options.
Speaking for lightsabers, I just tested it, and it appears that lightsabers do not cast ambient light, checking depth buffer shows why.
http://www.framecompare.com/image-compare/screenshotcomparison/9JJ9MNNU
Lightsabers blade does not have any 3d geometry, so RTGI does not know the position of the light to cast, at least that is what I think is happening.