Include cart attributes in CarrierService call?

[agiledigital]

Is there a way to include cart attribute data in the  call made by Shopify to our carrier service?

We’re collecting data via custom cart attributes and we need this information to help us determine the shipping costs, however it doesn’t appear to be passed in the carrier service call to our app by default. 

[MSuki93]

@agiledigital Did you find a workaround for this? I'm trying to do the exact same and have hit a wall.