@strawberryfieldsforever That warning message is indicating that the write method needed for manjaro (dd) doesn't match the default write method that rufus uses (ISO/file) so it has no option but to use dd. Since rufus does support writing in dd, all this warning is saying is that the default options can't be used, but dismissing it and continuing will still result in a bootable USB.
@Le3Kat
alrighty, so, am gonna go ahead with the installation! π