It’s off topic here, so I will move to a better place.
If you want to install multi OS, the only limitation is the VIM devices don’t have enough storage room, normally, Android will need 6GB+ room, and Ubuntu with desktop also need 4GB+ room, and OpenELEC/LibreELEC require 2GB+ …
Of course, you can try install some O/S on eMMC, and others on uSD card, you can looking around the forums for instructions.
We’ve release Android + Ubuntu DualOS for VIM Pro, you can refer Firmware Pages for the details.
You might also interest in 3-in-1 ROMs for VIM2 build by Balbes150.