On overlay designs the version compliance currently is read from the @base design. If you implement a basic-App-kit or basic-website-kit design you have no chance to define you own version compliance for you project and therefore often can't use new features.
This now has been changed.
Overlay designs may specify their own version compliance.
When rendering a TML OpenWGA will check, if the TML comes from the overlay design and use the overlay-version-compliance if so.