The Grub2 Beta 6 release had a bug and you may find some payload files were not listed in the menu.
This was due to the code which detects a 64-bit CPU having a bug - the BIT64 variable was never set! For example, \_ISO\MAINMENU\ubuntu.iso would not be displayed in the menu.
This is now fixed in Beta 7.
To update your Easy2Boot drive, download the new Beta 7 zip file and replace the UEFI_GRUB2_PTN2_Beta6.imgPTNLBAa23 file with UEFI_GRUB2_PTN2_Beta7.imgPTNLBAa23.
Recommended for Easy2Boot (fastest!) - SanDisk Extreme SDCZ880-128G-G46