This is the successfull procedure I adopted to create my multiboot USB drive with Ubuntu linux and Windows 10 (but you can put every bootable .iso or .zip file you want).
I have also tried SARDU and YUMI, but I couldn’t get them to work with UEFI.
Unfortunately the entire procedure only works on a Windows OS, if someone knows a way to do the same on linux just drop a comment line.
.iso or .zip files.iso and .zip files to .imgPTNMAKE_E2B_USB_DRIVE (run as admin).cmdNTFS.iso and .zip files to .imgPTN - go to extracted MPI Tool Pack (MakePartImage) tool
ImDisk\imdiskinst.exeCreateDesktopShortcuts.cmd.iso and .zip
.iso or .zip to the newly created desktop shortcut MPI_FAT32.iso or .zip it should have created the .imgPTN file.imgPTN files to \_ISO\MAINMENU of your USB driveMAKE_THIS_DRIVE_CONTIGUOUS.cmd from your USB driveIf you want to later add any other .iso or .zip, just start from step 4 (of course you can also delete any .imgPTN file you don’t want anymore).
Now that you have prepared your E2B drive, execute SWITCH_E2B.exe from your E2B drive in \_ISO folder and double click on the OS or tool that you wish to boot with. Next time you boot your computer you will be able to boot the selected OS or tool chosen.
To get back and choose another OS or tool to boot, go to e2b folder, execute SWITCH_E2B.exe and choose “Restore E2B partitions”.