Karlo Copp does, indeed, have credentials, but having impressive credentials is not, sadly, an obstacle to talking tosh. Some might say that 'incredible' in its original usage describes many of his ideas, particularly re: the F-111.
Upgrading the F-111, fitting it with F110 engines, etc, etc all looks good on paper, but the practicalities of doing this sort of thing are never as simple as they appear, and rarely costs as little as proponents suggest. It
sounds simple, but unless you virtually rebuild the airframes from scratch (see comment about selling Tasmania when thinking about the cost of this), you spend a lot of time and a fair deal of money on an airframe that is getting ancient and which will cost a considerable amount of time and money to maintain. At some point, you have to say 'great aircraft, but better to spend on something else, let's plan a great retirement bash for the old beast' and buy something new.