Lines and Snap as a Masking Method
I don't exactly know if this is a good place to suggest something, considering that I have no idea how to suggest it in the informer idea, but my suggestion has to do with masks in general, would it be possible to use it as a line and with snap?
Trying to explain myself better, let's say I have a building and apply Wall LoS, and then turn on ambient lighting, then use the mask to cover the building right away, but this would attach to the already created wall LoS.