That dampener modification make a lot of sense, although I never saw any dampener problems on the small block or 427 chevys during the time I spent at TRACO, and we did not make that modification then (on any of the engines I remember).
The only engine I remember having a dampener problem, as I mentioned previously, was a 454 block Chevy, where the dampener and crankshaft had to be balanced together, the dampener had additional material added in one area. That 454 was 1 of 2 used in a cigarette boat for offshore racing, and subjected to extreme over rev conditions, when the boat left the water and the throttles could not be pulled back fast enough. The pilot said it failed during one of the over revs.
I mentioned the 2 Bill Howells I knew in a previous post, Bill Howell (Davy Crockett) at TRACO was actually Walter Howell, but everyone called him "Bill", I'm not sure why Bill and not Walt.