NGRE through PaperUI is basically broken. Half of the rule triggers don’t work, the editors are flakey, and full support for rules was never completed.
As mentioned MainUI which includes creating rules through the UI will be supported on the apps and it already works well in the browser on mobile, even for creating rules.
PaperUI has been dead for a very long time (since it was abandonded by it’s maintainer) so you’re never going to get this sort of support unless you do it yourself.
There is no way for normal users to accidentally mess up configurations. Only users with an admin role can access administration things. Even the REST API is now locked down so they can’t even access the APIs without authentication. And there is nothing stopping you from using MainUI as your administration UI and BasicUI or HABPanel as your user’s interface.
Over all, your time and effort would be much better spent either moving to MainUI and OH 3 or figuring out a way to edit text based rules from your phone. NGRE in PaperUI is all but hopelessly broken and it’s not going to get fixed.