randi's two value argument is this.
I am a magician, and even so, I know that the physical laws of the universe as currently understood by scientists is true in all environments, therefore, Steorn is a fraudulent company.
a third value argument is this.
The laws of thermodynamics make claims regarding energy that have been verified for over 100 years in experimental physics. Claims that violate this law are not likely, but perhaps possible, and should be tested when reasonable claimants have taken reasonable steps to assure us against fraud or human error. Therefore, we do not yet know what Steorn has, but the likely hood of them being fraudulent seems highly unlikely at this stage. Steorn claims that they do not take thier claim lightly, and have tested in rigoursly for years. They also claim that they already know what the 12 scientists will conclude, and request that we suspend our belief until their tests are finished.
Notice how Randi's argument needs to have Steorn has a fraud or hoax for it to be correct, steorn 'must' be fraudulent. That's also a claim that can be verified, and that is where the argument crumbles.They must be fraudulent because his truth values are either true or false, there is not third value possibility.
There is no "third value" here. Either Steorn is fradulent or they aren't. Our personal opinions have absolutely nothing to do with empirical truth or falsehood of their claims. If Randi is wrong about them, that simply makes him wrong. It doesn't somehow make anything more or less true.
If I claim to make a magical device that breaks the laws of physics that in fact exists, my claim is true. It would require the re-examination of hundreds of years of physics research, but the claim would remain true. If I didn't demonstrate the claim, many people would rightly claim it is extremely unlikely to be true, but that wouldn't make it less true either.
Similarly, if my device did nothing, my belief that it worked would not make the claim less objectively false.
I still fail to see how your "third value" applies to objective truthfulness, and I am coming to believe from your examples that it is derived from a fundamental misunderstanding of terms. You talk about Randi's "truth values" but what you refer to is his opinion. He appears to be of the opinion that Steorn is fradulent. That doesn't influence whether or not they actually are fradulent.
As skeptics, most of us probably put a lot less weight on someone's claims than on the evidence they show that those claims are, in fact, true. Thus, we tend to assume the default position that amazing, laws-of-physics-breaking claims are probably not true, unless we are shown convincing evidence to the contrary.
Again, that doesn't influence objective truth. If someone shows me a 100% efficient power source that can be shown to actually work, I'll buy the damn thing.