Mine is a new installation of linux, so I never had chromium installed. So, there are no chromiums files to access. My problem is that there is no plugins directory that I can place links to necessary plugin; i.e., java, mplayer-plugin, etc. It finds the flashplayer-plugin ok.
I installed the iron-linux-64 directory in /usr/local and linked the iron wrapper to /usr/local/bin, so I can re-install the OS without requiring a new install of iron (and some other things) with each new install.
An easy solution would be to provide a plugins subdirectory within iron folder and search it last for plugins. Another would have iron search /usr/local/lib for plugin folders.