There are a number of COBOL development features that depend on the Microsoft Build Tools and Windows SDK packages. By default, the product installer downloads and installs these packages to their default locations. The installer then sets your COBOL environment to depend on those downloaded versions.
You can use the Microsoft Build Tools and Windows SDK Packages configuration utility - cblms - to view which versions are in use, and also configure your COBOL environment if you require something other than the standard usage.
For example, some project types (for example, .NET Core) require a different version of the Microsoft Build Tools (the Visual Studio 2019 version) than the one installed (the Visual Studio 2017 version). If you have already installed the correct version for .NET Core, run cblms after product installation, to update your environment to use the correct package.
There is an option within the product installer to skip the installation of the default packages (skipmstools=1); however, this does skip both packages, so make sure that you do already have the package(s) that you require before setting this - see Microsoft Package Dependencies for details on the package(s) you may require.