Is there a reason why you want to disable the System monitoring and security alerts?

As noted on the doc page, it actually configures multiple systems, so it'd be good to be clear on what you are actually trying to achieve. I.e. which systems you actually want disabled?

Also, I'm guessing that you're probably getting emails that you don't want to get? The point of these emails is that they provide useful info. If the info isn't useful for you and/or there is too much of it, then at the very least, there should be an easy way to disable that.

So assuming I'm on the right track, could you please tell me a bit more about the emails you're getting that you don't want? I suspect that unless you no longer plan to use TurnKey at all, adjusting config to reduce the annoyance is probably a much better path. Also, perhaps there is actually a bug somewhere that is causing you to get spammed? If that's the case, I'd love to know about it so we can fix it!

Assuming I'm on the right track and you're getting emails you don't want, please share the nature of the emails and where they are coming from - i.e. the sender of the email. Ideally please post the text of the emails you are getting (it's a good idea to redact any personal info such as email address, but please make it clear what parts have been redacted).