UE4 Disable to UnityBuild Configuation

BuildConfiguration.xml

<?xml version="1.0" encoding="utf-8" ?>
<Configuration xmlns="https://www.unrealengine.com/BuildConfiguration">
	<BuildConfiguration>
		<bUseUnityBuild>false</bUseUnityBuild>
		<bUsePCHFiles>false</bUsePCHFiles>
	</BuildConfiguration>
</Configuration>

bUseUnityBuild
Whether to unify C++ code into larger files for faster compilation.

bForceUnityBuild
Whether to force C++ source files to be combined into larger files for faster compilation.

bUseAdaptiveUnityBuild
Use a heuristic to determine which files are currently being iterated on and exclude them from unity blobs, result in faster incremental compile times. The current implementation uses the read-only flag to distinguish the working set, assuming that files will be made writable by the source control system if they are being modified. This is true for Perforce, but not for Git.

bAdaptiveUnityDisablesOptimizations
Disable optimization for files that are in the adaptive non-unity working set.

bAdaptiveUnityDisablesPCH
Disables force-included PCHs for files that are in the adaptive non-unity working set.

bAdaptiveUnityDisablesProjectPCHForProjectPrivate
Backing storage for bAdaptiveUnityDisablesProjectPCH.

bAdaptiveUnityCreatesDedicatedPCH
Creates a dedicated PCH for each source file in the working set, allowing faster iteration on cpp-only changes.

bAdaptiveUnityEnablesEditAndContinue
Creates a dedicated PCH for each source file in the working set, allowing faster iteration on cpp-only changes.

MinGameModuleSourceFilesForUnityBuild
The number of source files in a game module before unity build will be activated for that module. This allows small game modules to have faster iterative compile times for single files, at the expense of slower full rebuild times. This setting can be overridden by the bFasterWithoutUnity option in a module's Build.cs file.

Referer.
https://docs.unrealengine.com/en-US/Programming/BuildTools/UnrealBuildTool/BuildConfiguration/index.html