I have created a backup of my max2play image very easily with my method 3) above. If you already have Win32 Disk Imager, e.g. used to create your Max2play SD card in the first place then this seems by far the easiest method. What I did was the following.
1) Removed the SD card from my Pi and put it in a card reader attached to my PC.
2) Used Win32 Disk Imager to read the SD card and write an image file to my PC.
3) Formatted another SD card with the SD format utility (it had a Rasbian image on it, without a SD format the write fails)
4) Used Win32 Disk Imager to write the file just created onto the second SD card.
5) Booted my Pi from the second card. It came up perfectly with all my configuration as on the first card.
So I now have a duplicate SD card image, and an image file for my max2play configuration stored on my PC. Perfect!