In your BuildConfiguration.xml you can specifiy which compiler version to use. After the C++ 16.3 mess, I did.
(Pre 4.24 I used 14.22.27905)
<?xml version="1.0" encoding="utf-8" ?>
<Configuration xmlns="https://www.unrealengine.com/BuildConfiguration">
<WindowsPlatform>
<CompilerVersion>14.22.27906</CompilerVersion>
<Compiler>VisualStudio2019</Compiler>
</WindowsPlatform>
<VCProjectFileGenerator>
<Version>VisualStudio2019</Version>
</VCProjectFileGenerator>
</Configuration>