Does anyone know this? Would it be possible to install a symbolic link between a directory on the internal memory and the SD card so that the contents of the directory on the internal memory appear there on the SD card? Yes, different file systems.
I think that the media partition (internal storage) may be up before the SDCard.
If I’m right, this may bring lot of problems, for example with the media scanner triggered on boot.
Files may be referenced twice by the media scanner, of not included in database with internal storage path.
Not speaking about the different FS, unknown behavior.
Anyway, this worth a try 