I finally figured out the "unchain" process a few days ago. Before that I was using stealth to get around it.
But yeah, there are many locations where auto-chain gets you in trouble. For example, there's a way into the blighted village which circumvents the front door encounter using jump. But if you don't unchain first, the rest of your party auto-paths through the main gate, triggering the ambush cinematic/combat.
IMHO a "solo mode" button would be more intuitive than the unchain thing.
