vim and neovim support a few flags for opening multiple files, -d for opening in side-by-side diff mode, -o/-O for opening multiple windows stacked vertically/horizontally, -p to open in multiple tabs, etc. gnvim supports opening splits and diffs from within nvim after starting it, but doesn't support those multiple-file options. If I try to pass flags like that when launching gnvim, I get errors like error: Found argument '-d' which wasn't expected, or isn't valid in this context.

Is it intentional not to support those flags, or could they be added?