It would be truly fantastic if they offered more couriers. They offer way too little as is (even adding more couriers not integrated with the map would be a good idea, guys!)
Firstly, I want to thank you for considering our app and giving it a try!
Know we had a chance to connect directly on this, but wanted to reiterate that we hear you on the number of compatible couriers, and echo your concerns. In our app listing, we try our best to communicate that our app functions by generating a page that allows customers to easily be directed to their Shopify order confirmation page. This page is owned, and operated by Shopify so we as the app developers do not have control nor access to offer more carriers.
Our team is in close discussion with Shopify on an ongoing basis, so we are hopeful that more compatible carriers will be added to the list in the near future. Fingers crossed!
If there are any questions or if you wanted to re-connect, please contact us at firstname.lastname@example.org.
Co-Founder & Merchant Success Lead