Like previously mentioned, this new framework allows app development to introduce new features much more easily and unlocks a lot of potential for the app.
In the next release of mastercomfig 9, barring any more patches, you can expect to see support for class configs, crosshair customization, weapon customization and more advanced keybind setups.
These features are already near completion and are in the polish stage for bug fixing and visual enhancement. I can't wait to see what the community thinks about this, and hope the app becoming a one-stop shop for all TF2 customization provides value to all of you. I'm always open to feedback and new ideas, just let me know what you're thinking of!