Thanks, @ryandejaegher.
Yeah, I'd prefer to avoid option 2 as I'd rather everything else be the same, I just literally want to be able to have a couple of images be full-width, and preferably not confined to just the feature/headline image.
Do you have any suggestions of what might be suitable code and how I may be able to target specific images with it?
Or, alternatively, if there was css that could override certain sections/gallery choices to force them to be full-width?