agree with 4plex, the balcony, with or without the view, will add outdoor living space for your BIL’s neighbor.
as for your BIL being upset. the new homes in 4S is designed to maximize profit and minimize privacy. he knew that prior to the purchase. there’s absolutely nothing to be upset or surprised about.
btw, have you ever walked the older part of 4S vs. the newer part? the contrast is unreal. the parts south of Camino Del Norte are well planned, with lots of greens, yards are bigger. the homes north of Camino Del Norte are crammed in, with minimal yard space, with less green space, less tot lots, and with a much higher mello roos.
that’s what you get to buy at the peak or the beginning of the slide when the builders are focused on money and how to get out ASAP with the most of it.