What about rendering SH coefficients into an image for later re-lighting in Nuke

Has anyone here actually done any deep data productions ?
Everyone i talk to that seemingly has seemed to indicate that they reduced the layers to the absolute bare minimum (down to RGBAZ) due to filesizes and performance limitations. While i find the possibilities intriguing it seems somewhat limiting in other ways.
I took a look at some of the sampledata for 6.3. It isnt even a complex example (imagine atmospherics or other participating media, yikes) and already adds up to 520mb (!) for a single 2K frame.
That’s 3 Layers: Buildings (blue boxes), Balls (red spheres moving between them) and ground. Note that this is only RGBAZ + corresponding deep data. How on earth should network and even local discs handle that ?? Let alone the performance drag and doing anything deep based. I must be missing something big, as i don’t really see that working in a production. Without even adding in the data explosion due to additional renderelements.

Regards,
Thorsten