Tested using 083 Openbox Manjaro .iso;
1. Create LiveUSB using Unetbootin as usual
2. Do the following;
cp {usb root folder}/manjaro/boot/i686/manjaroiso {usb root folder}/ubnkern
cp {usb root folder}/manjaro/boot/i686/manjaro.img {usb root folder}/ubninit
3. Edit {usb root folder}/syslinux.cfg
4. If your USB drive label is PATRIOT for example – replace misolabel=MJRO_083 with misolabel=PATRIOT
5. Save changes to {usb root folder}/syslinux.cfg, restart choosing to boot using USB and Manjaro LiveUSB will load successfully
Pateo's Blog 
Thank you, very much appreciate the info.
DD would not actually allow me to EFI boot so unetbootin is the better option
[…] tous dans mon cas, mais j’ai finalement pu créer la clé qui allait fonctionner grâce à ce blog. Les plus de Manjaro ? Sous Fedora, les ventilateurs de mon Mac turbinaient en permanence, […]
Nice Article.
Also check out a method to Install a Persistent and Portable Manjaro Linux on a Flash Drive at https://www.techsolveprac.com/manjaro-on-flash-drive/