Hey @lamasgergo,
Thanks for the detailed explanation! I would say this would be a feature request at this point, and I’ll be happy to pass that on to our team for you.
As for workarounds, you could look at using the storefront API for this to retrieve the available rates within the buyers context: CartDeliveryGroupConnection - Storefront API
If you have some time, this guide on the storefront API carts may be useful as well to explore for alternatives: Cart