[whiterknight]

I promise, you will be just fine without the security updates.

[drawnwren]

This is probably misguided. Apple includes the OS version number in the user agent, so an attacker can actually pay to have code delivered only to users with vulnerable versions of MacOS. (advertising marketplaces allow bidding by user agent)

[whiterknight]

Are you thinking of a safari exploit that allows JavaScript to get out of the safari process? What’s the attack scenario?

[threeseed]

The user agent is defined by the browser.

And it only contains: Intel Mac OS X 10_15_7 irrespective of what Mac you are using.