I believe you indeed can do this, but you need to recompile GrapheneOS. Which brings me to another one of the turn-offs of GrapheneOS: you also need to recompil

I believe you indeed can do this, but you need to recompile GrapheneOS. Which brings me to another one of the turn-offs of GrapheneOS: you also need to recompile GrapheneOS if you want to have root access. I understand that it's for security, but compiling Android ROMs is generally painful and GrapheneOS is otherwise quite flexible is letting the user choose their own security/paranoia level.