Does Startapp Ads show inappropriate ads?

I have an app which is not designated for kids (Nickname generating tool). But, rated as 3+ in the Google Play Store as per the questionnaire .
My Question is, What is Startapp ads doesn’t match the Google’s Ad Policy. I am trying to switch from Admob to Startapp cause the eCPM is too low and the fill rate too. Only 50% of the requests is filled.

Google Ad Policy : Ads - Play Console Help

As said, A 7+ shouldn’t contain 13+ ads and a 13+ apps shouldn’t contain 18+ Ads. This is the thing that holds me from using Startapp ads.

Is Startapp ads safe to use?