I'm questioning the usefulness of this. Is it not enough to update the documentation that says "cacheHours by default is set to 8 hours, and document how to override it? Something like:

"If you feel is 8 hours is too long, feel free to override this option. If you follow best practices and never change image url assets, feel free to increase this to a week (cacheHours: 168)."

To me, this profiles object doesn't seem very useful. Feel free to win me over :)