Physical can be understood to mean "of or relating to matter and energy or the sciences dealing with them, especially physics." Light, temperature, and time are described by physics, so I would consider "physical" to be an accurate adjective for those units. You seem to be using a more limited definition of physical, closer to the word "spatial."

Also, btw, you might want to read the article you linked. The article is discussing a fringe idea that some scientists have. Scientists are free to explore new ideas, and they make for good click bait for science journalists. Until those ideas gain traction, they don't provide for compelling arguments, though.

That paper is not good.

I Special Relativity you have many cuadrivectors, for example:

* time-space (t, x, y, z)

* energy-omentum (E, px, py, pz)

* Electromagnetic Potencial (V, Ax, Ay, Az)

and even a few 4x4 matices like the electric and magnetic fields together.

All of them change with the same equations. You can't break (t, x, y, z) and keep all the other.

And there are extensions to particle physics that mix Special Relativity and Quantum Mechanics that use the same equations, and they have an agreement of theory and experiment of 8 digits. You can't break (t, x, y, z) and keep all the other!

Also, the paper is published in a journal I never heard about. It's impossible to be sure, but it has a lot of single author articles that is a big red flag, and the titles of the other articles are too weird (Nobel price or crackpot, nothing in between).