Thanks, very helpful guidance, since extra caution is always advisable around batteries for safety.
Fortunately, after your post gave me the courage I needed to take the knife out and plunge in, something miraculous happened. As I started running the Exacto blade along the part of the weld that was parted in the accident and toward the rest of the weld, an audible pop saw the seam settle in place and the Power button start functioning much like normal. It’s very sensitive to being pushed, but reacts appropriately. Before, if you touched the sundered case, it was obviously shorting or tweaking the button.
All in all, it could’ve been a lot worse, assuming this recovered functionality is retained. The buttons are scuffed, as is the front lower cover. But it works:slightly_smiling_face: