The little tutorial pop-up seemed to imply that the target next key was only used if the chaser perk was activated but I have no idea how to do that either through action keys or keymap file. I'm also curious to know if there is some sort of ship upgrade needed to use it.
This isn't really necessary for enjoying the game I understand, but I'm a space-sim buff and I like being able to target and match speeds with bad guys.
Well, for now I'll just run & gun and hope it's a future patch issue.