Hi
AI Ringtone does not work in this way . It will Base on the noise levels to decide the starting point of the ringtone volume but we will still gradually increase it to the set volume level - so in case you are away from your phone you actually hear it!
The functionality is to allow the gradual raising of volume, not a constant low or constant high.
For the overlapping issue in lockscreen are you able to provide a screenshot here?
Br
CH