VICE (x64, xscpu64, etc.) allows to load romsets (.vrs) and romset archive (.vra) files using the gui and it would make quite some sense to have a command line options allowing to load sets which are of course applied after vicerc is loaded.
Additionally, for the moment when a .vrs file is loaded using the GUI (gnomeui here) the current search path should be extended to the directory in which the .vrs file is located. Whenever the custom rom is not in the directory from which vice was started or the usual search path, resources without path are not found. With that limitation fixed it would be much easier to share romsets.