Update: I am able to dual boot on the Volla Tablet now

. There were some minor differences from the Quintus Wiki entry (Step 10 was the main difference)
Other notes/tips:
1. On the Tablet, an SD card is required. Be sure to format it as "Portable Storage."
2. I started with Volla OS. I am not sure how to proceed if you have Ubuntu Touch as your default OS.
3. Make sure you read directions and result screens carefully. Volla Boot Manager will give you an Android Style button when it is finished with time consuming processes.
4. Per Volla, "The second system, UbuntuTouch, may only be updated using the update function in Volla Boot Manager. Under no circumstances should you attempt to perform an update within UbuntuTouch."
From
https://wiki.volla.online/index.php?title=English ...
Please always note:
-> "No update/upgrade without a prior backup!"
-> ALWAYS format the SD card as "Portable Storage"!
-> NEVER format the SD card as "Internal Storage Extension"!
-> Never make significant changes to settings without background knowledge and knowing how to undo the changes.
-> REGULARLY CREATE BACKUPS OF ALL DATA AND VERIFY THEIR FUNCTIONALITY THROUGH TEST REIMPORTS