yalixie I see you have answers to most of your questions. System Diagnostics and CAT require Administrator roles to function. Due to the nature of Database, access is restricted to full Administrators. I will look to clarify the System User Interface Role for Database Page. Lastly, access for Non-Administrators to edit Extensibility Rules was reviewed by Product Management and determined to be functioning as designed, not a defect. The reason for this restriction is due to the potential impact on the health and performance an application.
Joseph Chimbolo
OneStream Product Advocate