Based upon some recent original 30 year old timing that I have replaced, that part of your statement above would result in my opinion of a resounding YES, replace the chain set.
The issue I am concerned about is not the chain, but the nylon or plastic teeth on the cam gear which will not only shows wear, but also many small cracks all around the gear.
Normal driving even with some boost would not be a concern to me, but WOT blasts for a sustained period would load the plastic gear much more than normal, or even just spirited driving.
If the gears ended their life at WOT you will not only replace the timing set, but also be removing the heads to replace valves.
In the early years I replaced a few original timing sets at 50-60K miles on GN's that were driven so hard the chains became loose enough to contact the timing cover because the teeth on the gear would be worn down almost to the metal part.