Let’s have a try with that 4.7 release…
Edit : I could make it with the 4.7 release !^^
I managed to backport 64-bit support to 4.5.1. I updated the UnrealBuildTool IOS module to the 4.6.1 one (fixing the few compilation errors that showed up), fixed four compilation errors in the MetalRHI module by adding a few explicit uint32 casts and used the 4.7 iPhonePackager.exe. I also had to hardcode the cfBundleExecutableName in my info.plist and change the minimum OS version from 6.0 to 6.1. I’ll look into moving to 4.7 after GDC.