My Gcode was 36MB, and it turned into a 15.4MB S3G file without any problems . . . I always use the SD card, so once I make the SG3 , I typically ditch the gcode file.
I am using RepG 0024 . . . other than time it always seem to handle the high-resolution stuff fine.
Feel free to turn fuss with the $fn= in the *.scad it is crazy fine resolution as is.