Thanks for the replies, discussion, resources, and stories! I appreciate it.
To summarize what I’ve been reading, potential dangers of exceeding power-on Vne include: negative effects on controllability, reduced service life on aircraft components, and resultant inaccuracy of time-change component schedules. If it’s exceeded by 10%, you *may* run into problems with compressibility, excessive vibration/aircraft stress, blade stall, or some combination of all of the above. Did I miss anything big there?