I'm loving Sandboxed Google Play, but it keeps trying to install "Google Play Services for AR". I assume it's a default app, as I've never used it nor even understand what it is. But I can only tell it not to install it and then a couple hours later the icon is on my home screen again with the caption "Pending...".

Is there any way to block Play Store from installing this? Or will that break something?

Thanks!

It is a dependency that apps like Google Camera (and other apps with AR features) can use. Play Store is used to being able able to install dependencies as they come, but with Sandboxed Google Play, it has to ask you before installing it, cause it doesn't have the privileges of installing/uninstall packages on its own.

I recommend installing it and leaving it, it's fine. GrapheneOS also provides an option to disable user-installed apps, so you can install it and disable it if it bothers you.