devotessential Is there any documentation anywhere that says that?
Not specifically. Aurora Store is open source, you can check out the project and maybe contact the developers if you're concerned and have questions: https://gitlab.com/AuroraOSS/AuroraStore
devotessential is there any security issues I need to be concerned about?
Well it is less secure than using the Play Store since it adds a party to the equation (you have to trust the Aurora Store devs on top of Google's servers). It also doesn't implement security features like certificate pinning, although I'm not knowledgeable about what that implies. There's no obvious gaping hole that makes it an absolute no-go, if that's what you're asking.
I have used it in the past, without issues. Whether it's secure enough depends on your requirements.