This is probably related to this question:
but fiddling with the iTerm2 key mappings (both general and per-profile) to un-map option plus the left and right arrow keys still doesn't work right for me with zsh command line actions.
With Terminal.app, those option + arrow combinations go back and forward on the command line by word (space-separated blob basically).
I'd love to be able to do that with iTerm2, but despite my having asked for the mappings for the combinations to be removed they still don't work.
Ironically the main reason I installed iTerm2 was to be able to disable the (to me) insane behavior of command-p (print), which had wasted a bunch of my printer paper.
When I bring up Terminal.app, those key combinations work properly, so I think my zsh setup is correct.