Build "Project only" triggers Qt steps (moc, lupdate) in referenced projects

We have e.g. a ProjectA, which has a project reference to ProjectB (for linking).

When executing "Project Only | Build Only ProjectA" in VisualStudio or with msbuild on command line via option "/p:BuildProjectReferences=false", then not only the moc steps of ProjectA are executed, it also executes the moc steps of ProjectB.

It looks like this is related to the following dependency tree in msbuild targets:

AddPublicBMIsToProjectsInfoForReference
    FixupCLCompileOptions
        QtUpdateCompilerOptions
            QtAddCompilerSources
                QtWork
                    QtVarsLoad
                    QtWorkPrepare

We have (tried) to disable the execution of qt tools during design time by setting
<QtToolsDesignTime>false</QtToolsDesignTime> in qt_defaults.props .

Is there a way to avoid/control that the steps of referenced projects are triggered when we try to use "project only" builds ?