Classical critical slowing down (CSD) predicts τ _ relax ~ ε^-β near a bifurcation. We derive from two canon-published IDT theorems that physical-time relaxation yields τ ᵣelaxᵖhys ~ ε^-2β: a double scaling exponent arising from the Generalised Structural Inertia M (ω) and the reparametrisation dt = M (ω) dτ. Numerical simulation confirms slopes −1. 000 (CSD) and −2. 000 (IDT) to machine precision. The 2017 Taniguchi et al. experiment on STNO is fully consistent: they measured in the ε ∈ 0. 1, 1. 0 regime where both theories agree. A November 2025 experiment by Devolder et al. (arXiv: 2511. 10450) observes a divergent incubation delay at the magnon scattering threshold but does not measure the scaling exponent. We show the IDT-distinctive signal requires ε < 0. 05, and provide a complete experimental protocol for immediate testing via µ-BLS on vortex STNO. Builds on: IDT P3 (10. 5281/zenodo. 18948975) · P7 v2. 1 (10. 5281/zenodo. 18995629) · GAP3 (10. 5281/zenodo. 19014454)
Aleksei Sadovnikov (Tue,) studied this question.