You still have up and down control as well as lateral and yaw so I guess that's full control. You just have to give it almost 100% up throttle to keep it in the air but you can make it hover when it's trying to come down.I set mine at 25% & 15% as I am normally a bit further away most of the time. Your 30% Low Battery Warning should be just that, a red flashing banner that says Low Battery Warning, it should not start the auto-land until the Critical Low battery warning, which is the second level, this level is dynamic and will increase with range. Check where your warning levels are set and adjust as needed, keeping in mind that when you hit the Critical level the bird will land where it is and you have very little control, just some lateral movement.
The issue here is the lack of power available to you. If it wants to land the best thing you can do is to let it at once, just using lateral control to pick a spot if it is LOS. I tried to keep my P2 in the air by using full up throttle and it sucked the last bit of power very fast, and the motors just shut off while still 8' in the air. Lucky for me it was over grass, but I still needed a new shell as it sprung an arm. The word 'Critical' in this case means just that. I would personally never fly a battery down to less than 10% just for maintenance, that is why I have a plug in battery conditioner, it will take the battery down to 5% without it being in the A/C and shut off automatically.You still have up and down control as well as lateral and yaw so I guess that's full control. You just have to give it almost 100% up throttle to keep it in the air but you can make it hover when it's trying to come down.
I know this because my 2nd critical is set to 10% but when I take a battery on its 11th charge to 8% before landing (battery break-in) I have to hold it for that last 2% while it's trying to come down.