You appear to be in agreement with apatentlawyer in that extrinsic evidence has very little weight in a Markman. Yes, it may be used, but only for clarification of the intrinsic evidence, which is paramount, as you have quoted:

“In sum, extrinsic evidence may be useful to the court, but it is unlikely to result in a reliable interpretation of patent claim scope unless considered in the context of the intrinsic evidence."

The posts have appeared neutral and until such time as ronran categorically refutes them as biased, I will continue to welcome them.

Be well