I've been writing custom scripts for mobile OSRS on my phone (Android) using Ankulua.
Been doing this on and off for 2 years and have yet to be banned. Have gotten 10+ 99s running 2 - 10 hours a day (depends on what I'm doing that day since it's running on my phone).
I don't know if it's because I'm doing it on mobile, or if it's because they're my own private scripts that I've written to act like how I would play. I know lots of people say botting on mobile is safer, but it could also be just because I don't share my scripts with anyone else.