Layout Object for tabBar

I am trying to make the ExecDashboard Example in Architect.

First I used the Responsive Dashboard Tutorial and then started updating the code from the ExecDashboard Example Files.

The one piece I cannot do within Architect is change the tabBar layout to an Object so I can replicate this code:

Code:

    tabBar: {
        flex: 1,
        layout: {
            align: 'stretch',
            overflowHandler: 'none'
        }
    },

the layout config in Architect is restricted to a dropdown?

If I save my project and then manually update the Code outside of architect and build it the tabbar stretches as expected.

If possible I don't want to have to step outside of Architect because of this limitation,

Layout Object for tabBar