After deploying a bootstrapped msbuild and rebuilding a simple project, the output window will show projects have MSBuildDisableFeaturesFromStart=999.999, despite it being set to 16.5 in the environment vars section.

Haven't tested this out in many other scenarios as I just noticed this.

I'm only seeing it in the output window.

Rough data for the projects that show this:

9> MSBuildProjectFile = TaskWithDependency.csproj = 999.999, then later in the same project output I see it set to 16.8 (expected)
10>Done building project "Microsoft.Build.CommandLine.UnitTests.csproj"
11> Additional Properties for project "Microsoft.Build.Tasks.UnitTests.csproj":

Will update as I dig into it. This is with verbosity forced to diagnostic.