ok - got the Khadas VIM3 working on Manjaro 22-02.
Create a SDCARD using etcher or similar using the vim3 image from the Manjaro site
1a. I found a very cool python script that runs in a gui ( manjaro-arm-flasher)
1b. There is a manjaro package that can be installed via pacman “manjaro-arm-installer”
Boot the SDCARD in the VIM3 - use “keys mode”
Power on VIM3.
Long press the POWER key without releasing it.
Short press the ‘Reset’ key and release it.
Count for 2 to 3 seconds, then release the POWER key to enter into Upgrade Mode. You will see the sys-led turn ON when you’ve entered Upgrade Mode.
I run “lsblk” to see what drive is being used.
Install manjaro-arm-flasher on the sdcard and execute the python script
You can now install the new manjaro 22-02 to the eMMC
once installed - remove the sdcard and the VIM3 boots into the new Manjaro - I had to use the gui to complete the new set up.