Speeding up initial mission lighting in 1.5.2?

I've gotten back to working with TGE recently, and was wanting to use 1.5.2 instead of 1.4.2 I had been using previously (yes, it has been a long time...) It seems like 1.5.2 takes much longer to do the first lighting of a mission than 1.4.2 did. I assume it has something to do with the Lighting Kit being integrated. I know that the lighting info gets stored and that subsequent runs of the mission won't have that issue. However, the game I'm working on randomly generates terrain for each mission, so I never get the benefit of using the stored info.

I would like to use the most recent build, and most current resources are for 1.5.2, so is there any way to speed up the initial lighting? Even if it forfeits some of the new toys of the Lighting Kit?

Thanks!