Hey I happened to pass over this thread and be mildly interested -- is there any chance you could post information about what is in your ability editor for this Omnilight ability? I'm not certain that I totally understand the original goal.
If this ability is one that truly emits an omnilight around a particular unit, you might have another issue here based on the limit of the number of light emitters that can show in the game at a time. It was not clear to me if you were having a problem like that. I don't have that much information about your original problem (based on what is in your original post).
My first post on Hive in 2008 about 14 years ago was on this same topic, and as far as I know it was not ever really exactly solved. There are weird limitations to this game engine. So I was curious if you were having a problem like that.