firejail opera browser with --private-option

I´ve created a portable version of the opera-browser (see https://gist.github.com/ruario/8416e36372f1a976a713 ). In order to open it I've got to type the command opera-developer_27.0.1670.0_amd64/run & in the respective directory. This works quite well. But when trying to run it within firejail using the command firejail opera-developer_27.0.1670.0_amd64/run & it won't work. Using the "--noprofile"-option however gives me fine results. So "firejail --noprofile opera-developer_27.0.1670.0_amd64/run &" works alright. Yet what I really want to do is running it with the "--private" option. So firejail --private=[path to a specified working directory] opera-developer_27.0.1670.0_amd64/run & would be nice. Yet I found out that this very command cannot work together with the "--noprofile" option. Is there a way to start my portable opera-browser within firejail using the --private-option? System is: Linux/Lubuntu 16.04.3 LTS, 64 bit