Problem has been solved; basically though I love the idea of the projector's abandon function [ie it can be 'destroyed' but the projection persists X seconds and fades out smoothly; thus saving the upkeep for a dynamic actor each tick, etc]. Problem is my game requires environments to be 'reset' dynamically, meaning that everything is perfectly reset save for scorch marks and the like.
As it turns out, if you leave out the abandon line, the projector will function _exactly_ the same way, unless you call Destroy()... at which point the decal is _gone_. I was worried that I would lose fade-out of dead projectors, but as long as they expire by lifespan, this seems to keep happening.