You don't appear to be the maintainer of this port so I am removing the "maintainer" keyword. I have assigned the ticket to the port's actual maintainer.
You don't need to Cc yourself; you will automatically be Cc'd because you are the reporter.
The ffmpeg port tells you about the consequences of selecting the nonfree variant to ensure that you're aware of the licensing implications of your choice.
I agree there is a problem here: orfeotoolbox declares a build conflict with openjpeg15, yet declares a dependency on opencv which depends on ffmpeg which depends on openjpeg15; this cannot work.