I've always heard that a cousin's friend's brother's inlaw coworker gave someone a jump, and a city block burned down, so you can't be too careful.
Electronic gizmos are expensive. It is unknown just how much reverse protection they put into them. I do believe the various electrical systems are design to different levels of protection: brake related sensors are designed to withstand reverse battery without damage, airbags used to (still are?) designed to work with the battery removed, etc.
But electronic gizmos that draw loads of power are less likely to have reverse battery protection, by virtue that the low cost methods of protection cost too much in power--and the low power loss methods cost too much money. Also I don't think jump starting cars is as common as it used to be -- so there may be less incentive (to the manufacturer) to design for it.
Beats me. I'd be interested in hearing more.