We have run into a couple of use cases with our custoemers where we must restrict who can view / edit what Orders and Carts in HubSpot.
In addition, we added a few custom fields to both objects. We also need to restrict who can view these custom fields.
At this stage, as I understand, these features are not supported by HubSpot natively. I would like to submit an official request to add this in. Happy to sponsor a few pizzas for the hackathon to accelerate the implementation 
