"A third part room sized calorimeter" and no one focused his answer on the first two words, "third part", and this is a key part of my "silly" idea.
You mean "third party." This would be a testing facility. However, here are "third party" consulting companies, SRI is a major one. Earthtech has what they called MOAC, the Mother of All Calorimeters, a large Seebeck calorimeter. Calorimetry, though, is well understood by experts. It's relatively cheap to do it right. That is, research is not being inhibited by lack of some calorimetric testing facility.
Moving all experiments to a facility would be onerous, and unnecessarily so. What the field expects is carefully performed experiments, well-documented so that they are reproducible. And then independent replication. There is no "third party." Third party is a Rossi-ism, used to mean supposedly independent experts. Chosen by him.
That kind of thing might be done if some controversy remains after a series of independent replications. The Rossi--IH Agreement used a single ERV, a very primitive form of "third party," defective because of how the ERV was chosen. IH knew this, knew that the eRV was not necessarily neutral, but went ahead for reasons that are clear to those who knew the situation then.
Rather, a more sober business relationship would have each party choose an expert, and then the two experts choose a third, who becomes the ERV, if it is going to be one person, and the ERV report would be subject to a review process, because any expert can make mistakes. The review process might, after review, have the three chosen experts vote. Having a single ERV would only be expected to work if that single expert is trusted by both sides, and Rossi seems not to understand ordinary business, arms-length, process, and imagined that he could force IH to pay even if they were dissatisfied, after all, they had "given their word." But Rossi did not keep his own word, and that's a common saying: when you point a finger at another, there are three fingers pointing back at you.