This was my solution. You might want to change the dimensions to fit your case. I also made one for the ‘Xperia XZ 1 compact’.
I added some clothed tape at one side to get the friction just right. The silicon case helps with holding the phone in place. It won’t fall out since you first have to lift the phone and then pull it out.
Hope can also help someone else
The author marked this model as their own original creation.