The article concludes: "It will be possible to measure the distortion of time with the data delivered by these surveys," Bonvin said. "This is very interesting because, for the first time, we will be able to compare the distortion of time with that of space, to test if general relativity is valid, and we will also be able to compare the distortion of time with the velocity of galaxies, to see if Euler's equation is valid. With one new measurement, we will be able to test two fundamental laws."
Okay, what happened with this report where time dilation is tested and claimed to support GR using high redshift quasars?
Quasar 'clocks' show the universe was five times slower soon after the Big Bang,
https://phys.org/news/2023-06-quasar-clocks-universe-slower-big.html
ref - Detection of the cosmological time dilation of high-redshift quasars,
https://www.nature.com/articles/s41550-023-02029-2, 03-July-2023.
My note, using the age for the universe at about 1E+9 years old (1 Gyr) and Ned Wright cosmology calculator (
https://lambda.gsfc.nasa.gov/toolbox/calculators.html), I get z about 6.0 for the redshift. This indicates time dilation support for the GR metric used to show expanding space. At redshift 6, comoving radial distance 27.487 Gly. Using H0 = 69 km/s/Mpc, space expands at 1.9396649E+00 or about 1.94 x c velocity. This must be true too when accepting the time dilation explanation for the distant quasars in the study. The origin of the SMBH seen, remains difficult to account for in BB cosmology.