I find that I must explicitly set a width in order for a Kendo React Chart to fill the parent's width if it is inside a Kendo React TabStrip.
This is true for any version of kendo-react-layout newer than 1.2.0-dev.201806281338.
This demonstrates the issue: https://stackblitz.com/edit/react-armuz6
Notice the chart outside of the TabStrip takes up the available width but the chart inside the TabStrip does not.
Also worth noting that other components that I nest inside of the TabStrip do not exhibit this. They take up the full width as expected.