Quote Originally Posted by Anonymoose View Post
At first glance, it has the risk of being one of those things where ... like ... something was impossible mainly because they story needed it to be in order to function, and now that part of the story is over, so to expand possibilities they immediately reveal that it's totally possible and actually quite easy "now that we know what we know" (see: tempering-curing porxie). Obviously - in real life - the sudden realization of a possibility that fundamentally eases the difficulty of a task is a thing that happens pretty regularly. But - in fiction - when such an event more or less perfectly coincides with the plot's needs and limitations and doesn't feel integrated into the big picture very well, it just feels like a cheap shuffling of plot devices to ease constraints on the writer, narrative quality be damned.
I actually think something important to keep in mind is that the key actually isn't very easy to use at all. The lalafel of the South Sea Isles successfully used it, but Robor and Alayla mentioned that they failed to use it themselves for a long time before Preservation stepped in. And honestly, it's kinda hard to say how much of what happened 'on-screen' in Dawntrail was the key's doing.

That suggests to me that the key's actually much harder to use than we might be giving it credit for. Hell, perhaps 'key' is more literal than we're assuming, and it actually does barely anything unless it's put in the right machine.