On #1. No-one has, other than speculating, confirmed the option is cost difference (there are hundreds of options for the 737 series, many of which are just co

On #1. No-one has, other than speculating, confirmed the option is cost difference (there are hundreds of options for the 737 series, many of which are just configuration differences). In the case of the indicator, there would need to be additional training, so airlines may opt not to have it to save on training, since it is not required.