Unreal Build Tool, set source control provider

Development Platform & Builds
,
1

Unreal Build Tool (UBT) contains this member

	static class SourceFileWorkingSet
	{
		enum ProviderType
		{
			None,
			Default,
			Perforce,
			Git
		};

		[XmlConfigFile]
		static ProviderType Provider = ProviderType.Default;

But I cannot see any way to change the Provider without modifying the UBT source. Is there an Xml Config file somewhere I can modify? The code seems to imply it, but I can’t find where it is stored or even read from.

(FYI, I need to change this to ProviderType.None since the UBT “ProviderType,Default” logic seems to end up assuming I am using Perforce, which I’m not, and ends up excluding all my files from Unity builds, leading to a very long compile time.