I propose introducing time-based controls for browser add-ons. The combination of the website-specific add-on feature with duration options would give users greater flexibility and security when using add-ons.
Possible duration options could include:
- Always
 - "Until idle" - Enabled until a period of inactivity
 - "Until tab closes" - Active only while the tab is open
 - "Until browser closes" - Enabled for the entire browsing session
 - "1 hour," "2 hours," "3 hours" - Set time limits
 - "Custom" - Allows users to define a specific duration