Hi @bliss-box
This is something which might be possible using our app ShipMagic. You won’t be able to offer discount, but you will be able to show only the highest rate when cart contains items from 2 different profiles. Attaching a video of how the app can handle it here.
Note: If you are using any automatic discount app? Like wholesale, bundle, volume, etc.. because such an app generates draft orders and this app does not work on draft order checkout.