I have already read the pages you have linked to and they do not answer my question.
I am not interested in the age-based filter because I want to block ALL apps and the most restrictive setting will still allow those rated at 3+
I am not interested in blocking apps once they have been installed since my child will already have had the chance to run them.
I want to be able to prevent ALL apps from being installed by my child, in a similar way that I can prevent ALL website URLs from being accessed.
Is there a way I can do this using family safety or not?