Finding instances which are the exception, especially in law, are exceptional because they are at odds with the accepted.

The body of law has evolved on the basis of precedent in that, given a similar set of circumstances, there will be a similar result. This certainty underpins the legal process. Notwithstanding Statute, change to the process can be slow, unless a new precedent is set eg Markman. That then becomes the standard by which all similar cases are based(certainty).

Obviously the law resists change, if only so the practitioners don't have to discard years of training and learn afresh. This is the case with intrinsic vs extrinsic evidence, I suggest(corrections more than welcome). Let the evidence speak for itself. However, linguistic nuance now means that what was once straight forward is complicated by not only the exponential growth in knowledge but also the adoption of words that can have a different meaning in a professional context to that of everyday use.

This is where extrinsic evidence may play a part, but need not as a legal requirement. It is not to prove what was in the mind of the patentee at the time of the patent submission(the patent application -intrinsic-covers that)but what those working in the field of expertise at the time would understand the application to mean, varying together, for example.

As you so rightly quote,

Vitronics merely warned courts not to rely on extrinsic evidence in claim construction to contradict the meaning of claims discernible from thoughtful examination of the claims, the written description, and the prosecution history--the intrinsic evidence ... '[Expert] testimony [on the proper construction of a disputed claim term] may only be relied upon if the patent documents, taken as a whole, are insufficient to enable the court to construe disputed claim terms. Such instances will rarely, if ever, occur.

Be well