Well, now I had to try. After some fiddling (noise reduction, wavelets, as you proposed) with a 36 mp NEF file, RT crashed, and it wasn’t able to open a 50 mp CR2. Still, with my 18 mp files, it works better than it should dare.
The host win7 computer is four years old, with an i5 processor and 16 GB of memory. They don’t get old as fast as they used to. And, of course, congratulations for your optimizations!