I understand doc provider wont come to android app in reasonable future.
But the android app is, to be honest, not very useable.
my files are organized into 10 levels of folders,
and now for each file i have to MANUALLY choose into 10 levels of folders, which is painful.
I think the easiest way to make it useful at the moment,
is to add shortcuts/favorite folders/files.
Pls expect the folder/file list will be a long list.
thank you.
Some with me 
I use also Cryptomator on my Android phone with well organized folder structures. Accessing a huge cloud storage (pCloud in my case) with all my personal documents and files.
Favorites (Folders) would be a big wish also from my side.
Worst scenario is when you need to switch between two different deep located folders frequently. It feels more like a maze adventure game app than a folder browser app 
The more you are sorting and organizing things the more folders and subfolders you need to handle. And 5 levels down and up and down… is not very efficient or convenient working. Meanwhile i do many thing just by smartphone and not only on my PC. So it becomes more and more important in my usage.
Is there any known plan for this feature? I was also double checking Github before posting this. But i did not find any feature item on that.