The oversized engine was technically usable, but definitely bothering me on an aesthetic level. But I'm so used to the RealPlume rocket effects that uninstalling the mod would bother me just as much on all the rocket engines.
Regardless, I have fixed the sizing issue and disabled all RealPlume jet engine effects until somebody can make some good ones. I only hope that, if the author doesn't return, the mod can survive the 1.1 changeover. I don't have much RAM to spare for cosmetic mods right now, but I plan on installing all the prettifying mods once we get 64-bit working.