Address type validation
The UPS API has the ability to differentiate between a residential and commercial address. Currently we only have the option to tell UPS that all address are 1 or the other. This is an automatic feature UPS provides that should be incorporated into the plugin. Without it you would be charging the residential fees to all the commercial customers or losing money on all the residential shipping.
I'm quite surprised this isn't already integrated into the UPS extension, as it's exactly something you would think a lot of customers might need.