The APP needs a option to store (e.g. map-)files / all data of the APP, in the APP-storage. So that the APP doesn´t need read/write power/permission to the whole storage.
One problem is that many users still have app directory in /sdcard/navigator which this permission needs. Another problem is that we are using old API of storage access (to support old devices). There is no way to update Navigator (and keep it working on all devices) without this permission.
Hallo, I do not know if I can help you, but I can freely copy and delete files on my sd-card. Phone: Samsung Galaxy A3(2017), OS: Android 7.0. I connect the phone via USB to my PC, look in This PC and find a drive Galaxy A3(2017). I can now use this as every other drive on the PC. May be this helps you. Regards knibja.