Is there any plan in adding a switch to let the developer decide to let IL2CPP rebuild all of the .NET framework libraries or skip that step?
I understand the implications of rebuilding them all to reduce the final code size, but it would be tremendously helpful to be able to disable that behavior while developing the game as it would make compiling for platforms like iOS definitely quicker.
Cheers.
Actually, we’ve started to work on something just like this. See the forum thread here about incremental builds:
http://forum.unity3d.com/threads/incremental-builds-for-il2cpp.365470/
We are still converting all of the assemblies from IL to C++ each time, but the generated C++ code is created so that Xcode should not have to rebuild the .NET framework class libraries for changes to use script code. The code generation is not quite as stable as we would like in this respect, but we will continue improving it in the coming weeks.
Thanks Josh! I wasn’t aware this was being worked on. I’ll get the latest patch release of 5.2.2 and play around with it.
Super! 
Thanks! Please feel free to discuss any issue on the forums here, and we’ll be happy to look at bugs or ways we can improve the incremental builds.