Correct there is not an MV option today for changing settings in bulk. But this is becoming a more common wish. Please do share your requirements and use case with your Meraki reps so they can add to the feature request, and hopefully you'll see this feature sooner rather than later.
Thanks, wishes are good, but please also get that info to local Meraki reps. Make a wish does filter back to the product teams but is not a feature request tool. We have a formal FR mechanism that Meraki reps can access and update accordingly.