Is it possible to rebuild a single module and copy it to the launcher version of the engine? In theory - yes, but in practice - looks like a check at the version revision blocks it.
I’ve had the same problem, and I think I’ve solved it (emphasis on ‘think’). Download the GIT version, change in the ‘Version.h’ file the version with the ‘Version.h’ file from the launcher version, compile and swap the DLL and the LIB that you require.
I’ve done that to solve in UE 4.18 a bug that was reported and solved here: Unreal Engine Issues and Bug Tracker (UE-93152) and I’ve just replaced the ‘Renderer.dll’ and ‘Renderer.lib’ with my version. I think that solved the issue, but I’m not entirely sure how are the DLL’s and LIB’s build in shipping. (was thinking to do the same with Unreal Engine Issues and Bug Tracker (UE-52220) )
An idea is to do that, insert some print in the engine loop and see if it works, I’ll do that later, and come back with feedback here, maybe it can help someone.