So, my question is whether the "cosmological constant" is, in fact, a constant to begin with.
You're not the only one who is puzzled. Unzicker warns that NO ONE knows what that is. Not even Einstein knew what that idea of his really meant.
Unzicker is an iconoclast. He is one of those who think that physics is in a state of utter chaos and that we are all being swindled. Physics is like a caravan with a blind guide making it go around in circles endlessly on an empty plain. If they had any eyesight, they would see lofty mountains far away that will never be reached.
The Standard Theory (of particle physics), he tells us, is part of this mess. It makes too many assumptions, has too many unexplained parameters. Its devotees say it managed to simplify matters wonderfully, but after so many years of discovering new particles in the bubble chambers every few weeks, until they had hundreds of them, ANYTHING that would boil it all down to just a few would have been a miraculous feat. It almost reached a point where if you hadn't discovered a new one then you were a fourth-rate scientist.
Then there's "the Higgs fake", the title of a book of his. They haven't discovered any "God particle" that magically explains why things have mass. They managed to trick the Nobel Committee into believing that they had and that they deserved a Nobel prize, but their purpose was to justify throwing ever more money on useless "atom-smashers" it would take you about two to three hours to go around if you used a bike.
He doesn 't include Penrose in his crowd of "overhyped physicists". In a video that deflates Steven Weinberg he quotes Penrose's book titled The Road to Reality -- A Complete Guide to the Laws of Physics, which deflates Alan Guth's cosmological inflation, thus: "Since I believe that there are powerful reasons for doubting the very basis of inflationary cosmology, I should not refrain from presenting the reasons to the reader."
All of this corroborates what is said in the book I have already mentioned elsewhere, one titled Betrayers of the Truth -- Fraud and Deceit in the Halls of Science.
In another YouTube video, "Why quantum mechanics is an inconsistent theory -- Roger Penrose and Jordan Peterson", Penrose says that the Schrodinger equation does not agree with the experimental data.