Improved Information-Coupled Scalar-Tensor Theory (i-ICST v11): Evolving Symmetron Coupling as the Origin of the Redshift-Dependent MOND Acceleration Scale — Calibration Against MUSE-DARK III

We present i-ICST v11, whose principal revision is the replacement of the v10 holographic formula for the MOND acceleration scale a0 with a physically motivated evolving Symmetron coupling mechanism calibrated against the MUSE-DARK III survey (Ciocan et al. 2026). The effective coupling is parameterised as: beta_eff(rho,z) = beta0_ref (1+z)^gamma sqrt[max(0, 1 - rho/rhoSSB(z))] with beta0_ref = 0.2963 and gamma = 1.06, yielding an effective MOND acceleration scale: a0_eff(z) = sqrt(1 + 2 beta_eff^2(z)) cH(z)/(2pi) The Symmetron screening threshold co-evolves as: rhoSSB(z) = rhoSSB0 (1+z)^3 ensuring that the cosmological background remains fully screened (Geff,cosmo = 1.0000) at all redshifts while the MOND enhancement grows inside galaxy halos. Fits against MUSE-DARK III redshift bins yield chi2/N = 3.01, compared to 4.37 for v10, corresponding to an improvement factor of 1.4x. The predicted a0(z=1) = 2.54 × 10^-10 m/s² agrees within 1-sigma with the MUSE measurement 2.38(+0.12/-0.10) × 10^-10 m/s². The SPARC RAR fit and S8 = 0.804 from v10 are preserved. Three critical issues from v10 are resolved, while two remain open.