Hi @Miki Ohtsubo ,
Welcome to Microsoft Q&A forum and thank you for the suggestion. We appreciate it. We will share and elevate your suggestion with the Azure Data Factory product team. We will keep this thread posted as we hear back from the product team.
Meanwhile, I would suggest you to provide feedback on the same:
Feedback Portal - Azure Data factory
All of the feedback you share in these forums will be monitored and reviewed by the Microsoft engineering teams responsible for building Azure.
Hope this will help. Please let us know if any further queries.