I don't think I can say I've had a 24bit file larger than 2gb's yet so I haven't experienced this. Do other programs like Sound Forge or Audition choke on files larger than 2gb? I use the izotope ozone mbit dithering plugin, which can be used in SF, I've never tried audition, but I'm sure you can use it there too.
All I'm using WL, SF, Audition for is for dithering anyway, and thats all done with the mbit plugin. So technically it doesn't matter which program i use to do that in.