No, it's not. At least I haven't found such possibility.
There is an option to mount container to certain folder, which might solve the issue, but you have to have 'sudo' installed to be able to do it, and unfortunately something is wrong:
tux is not in the sudoers file. This incident will be reported.
Any hints?
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All right, a bit deeper search, and I got what I need.
To have working sudo you need to add the user to sudoers file by
visudo
Than the game starts :) It's not that easy to write in this new modern fancy text editor :)
1. Press 'i' to turn writing mode on
2. append the file with tux ALL=(ALL) ALL
3. Press 'Esc'
4. Write 'ZZ' to save the file and exit
It just let's you to mount container to specified folder, still don't know how to change default file manager, but now it's not necessary anymore.