Custom iOS Notification Sounds due to decreased engagement

My server users are expressing dissatisfaction that they are missing out on a lot of activity due to the subtle notifications default on iOS mobile. iPhone users are not able to control any notification settings other than on or off. Users would have increased engagement if they were able to control notification features including:

1. Notification tone
2. Vibration settings

I'm not asking for complete control over each server, and channel's custom tones. But my community is seriously considering moving to another platform due to the lack of engagement caused by missing activity on iPhones.