There's already another older topic about this here: https://help.orrs.de/262/auto-carrier-detection
So no reason you created this identical topic too. Just vote for the other topic instead.
The competing AfterShip app has carrier auto detection, so it should be possible for Deliveries to do the same.
Here's another great feature in AfterShip that's missing is this Deliveries app too:
China Post tracking info in AfterShip is shown in English, in Deliveries it's only shown in Chinese.