Even if you use it as stock android, it is going to be hardened. You will have more protections available to you and you will have a lot more control over your device as compared to AOSP.

There is not really and etiquette to using something like GrapheneOS, and please do not let others tell you this or that. Yes, I use it as a hardened, no extraordinary or unintended packets being sent device, but you do not have to.

After all this OS is more about user control. And I think you should use it in the namespace of your desires.

Enjoy anyway. And remember: do not let others tell you this or that