Most games tend to look at anything that has rankings and leaderboards the most, so I would definitely recommend not using this for PVP. I would also say that special events are also risky.
At the end of the day though, if an admin or dev looks at your account and detects cheating at any aspect of the game they're going to ban you, even if it might not be permanent. You're just as liable to be banned for cheating in single player as you are for multiplayer, it's just a matter of what the admins and devs prioritize.
Based on experience from erogames's same game, don't ever use it in Arena. It may look like it's ok for a few times but if you continue to use it, you'd get permanently banned.
I suggest you use the bypass / non-modded apk version when doing Arena so that, you won't get reported / banned. Also, don't rush the story stages fast enough or else they'd notice you.