I have found out a key feature of the app. It will work fine if you're simply trying it out to see it it works. When you actually need it, it won't.
A couple of weeks ago I parked on a type 2 charger to go to the theatre. I walked about 200 yards from the car park to the theatre and up two flights of stairs, then realised I hadn't pressed the door button to lock the car. Fine, I thought, I'll use the app. No way. Every time it asked me to confirm that the car was secure, and when I did that, threw me back to the control panel screen without locking the car. I had to fight my way down the stairs again, against the human tide that was coming up, walk back to the car park (where the car was sitting with its DRLs blazing) and press the door button. Fortunately I made it back to the theatre in time to get into my seat before curtain-up. I have no idea if the fact that the car was charging at the time caused this. I don't see why is shouldn't be possible to lock the car while it's charging.
A couple of days ago I was staying in a hotel, and the car was in the car park, locked. I had left the key in my room, as I wasn't intending to use the car that day. However I decided I needed something that was in the car. Fine, I thought, I'll use the app. I walked out to the car park and tried to open the car with the app while standing right beside the thing. No way. Time after time I was informed that the operation had failed, try again later. I had to go back into the hotel and up to my room to collect the key.
That app is a snare and a delusion.