Thanks for your work on this!
Well for zip updates, I guess people modding their phones have a good chance to run a recovery (and for now that mostly means DoomKernel), when they're not trying custom kernels
Additionally, it's easy to unzip the update file and get the apk/framework individual files
As for 2g/3g switch, I had toyed with it on my old phone and did not bring any interesting results (same battery usage or sometimes worse). The reboot to recovery sounds more interesting
Unlocked rooted Sony Xperia S (stock)
Rooted Asus Transformer TF101 (Revolver ICS)
Old: rooted HTC Legend, S-OFF, CM7