[Zubersoft]

1) I can't do anything about the speed. That's just a factor of how slow the file I/O is using Google's API for SD cards. That is exactly why I was hesitant about supporting it for so long. My fears were justified - writing out files using the Storage Access Framework is incredibly slow compared to writing out files directly to the internal SD card (or the application data directory on the removable SD card).
2) Export as .msf worked without any issues for me when writing to the removable SD card. My tablet doesn't have the unusual restrictions yours does when it comes to the SD card though, so it's possible it's related to that.
3) That's a known bug in the Android OS that Google has never been addressed. You can see the bug report here: https://issuetracker.google.com/issues/36956498. Lots of users are annoyed about this. The only thing you can do to see your files is reboot the device or use network storage (that's what I do).
4) I exported a song as a .msf, deleted that song, reimported off the removable SD card, and it was created without issue. I'm going to need more information on how to reproduce this issue as it appears to work just fine for me.

Thanks,
Mike

[Vibraphon]

Hello Mike,
I still have bigger problems using the SD card:

• Restoring to SD card on Android 5.1.1 tablet takes 3 days (and 2 nights)!
  
• Restoring to SD card on Android 4.1.1 tablet (same backup) takes about 15 minutes.
  

1. Work around:
I only use the Android 4.1.1 tablet to restore from backups to SD-card (Changing SD cards between tablets).

• On Android 4.1.1 I can Expose Database File, even if MobileSheets Storage Location is set to SD card.
  
• On Android 5.1.1 I Expose Database File is not available when MobileSheets Storage Location is set to SD card.
  I cannot easy copy the mobilesheets.db file from Android 4.1.1 to Android 5.1.1
  

2. Work around:

• Remove SD-card from Android 5.1.1 tablet
  
• Clear Library
  
• Set Mobilesheets Storage Location to internal SD card
  
• Expose Database file
  
• Copy mobilesheets.db from from Android 4.1.1 tablet to \android\data\com.zubersoft.mobilesheetspro.files on Android 5.1.1
  
• Insert SD card from Android 4.1.1
  
• Uncheck Expose Database File
  
• Set Mobilesheets Storage Location to External SD card
  
• ... Puh
  

Is there a better way?

Paul