There is already a request for customizing the designer view through the API/SDKs in our system. It currently stands as a candidate, meaning that our product managers accepted this enhancement request but no release date has been confirmed. I will post back here once it is scheduled for a release.
The request hasn’t moved from the candidate stage. All candidates are evaluated on a quarterly basis by our Product Management to determine which enhancement requests goes on the roadmap. I will let you know once this is scheduled for a release.