So, perhaps this is rude, but I modified and re-compiled this wonderful mod for 1.2
I fixed lights affecting Kerbin from orbit, added RAPIER support and made hot engines glow (more details in release). It doesn't seem slower - but I have a fast-ish computer and haven't tested with 2000part rockets, ymmv.
Pictures:
http://imgur.com/a/Laf8N
I sent tajampi a message about a week ago offering to give them my changes and they've not replied (they did say they'd be busy I suppose) so unless/until they ask me to take it down you can find my 101% Unofficial version here: https://github.com/ToXik-yogHurt/EngineLightUnofficial/releases/tag/v1.0.0-gamma