More control over shipping dimensions and weight

I need way more control over the dimensions and weight that are used to generate my return labels. Right now there is just one size/weight that gets used for everything - but my return packages vary in size from 6×6×7 to 48×4×4 and in weight from <1 lb to >3 lbs. This is causing me headaches with extra audit fees from UPS when they have to adjust a package. When I talked to UPS about the issue, they instructed me to set the product dimensions as 0×0×0 when creating a return label. That way the item is measured when it hits the UPS sorting facility. However, EasyPost told me this was not possible. While the ability to set 0×0×0 dimensions would help, I really need the following functionality:

1. User creates a trade-in offer.

2. Based on the type of item being sent, the system then creates a label with the appropriate dimensions. This could be determined by simple rules using metadata flags on the catalog items. (note that the current custom mailing rules are not granular enough - and they only allow me to choose carriers - not set dimensions)

3. If there is more than one item, or the item is oversized, then the system does not generate a label but instead kicks off a workflow notice for my team to create a custom label.

This seems like pretty basic features to meet the needs of Reusely customers that are using the system for items other than electronic devices. Without this functionality I have to explore building my own shipping integration, which seriously reduces the value I’m getting from Reusely vs. an end-to-end custom solution,

Thanks!