We formulate a minimal open-system completion of the MetaTime program in which the observedStandard Model (SM) dynamics arises as a reduced boundary description interacting with unobservedbulk degrees of freedom. The extension is encoded by a causal non-Markovian influence functionalon the Schwinger–Keldysh closed-time path. The central control parameter is a dimensionlesslatency/impedance amplitude ΓL(µ) that measures dissipative strength relative to a characteristicboundary scale µ. In contrast to earlier drafts, we (i) enforce portal–renormalization consistencyby adopting a minimal safe irrelevant SM-singlet latency portal of scaling dimension ∆ = 6 andderiving the corresponding running exponent η ≃ 2(∆ − 4) = 4, while showing how electroweaksymmetry breaking produces an effective trace-coupling in the infrared; and (ii) derive an explicitprecision-spectroscopy constraint from the Markov/Lindblad limit of the influence functional: thelatency-induced homogeneous linewidth for an atomic transition n↔m obeys ∆νnm ≃γ2π(∆Lnm)2with γ = ΓL(µ)µ, where ∆Lnm is a portal matrix-element difference. Applying this to hydrogen1S–2S yields a falsifiable bound on ΓL(µH) given a matching scale ΛL. Finally, we connect the proton-persistence barrier Seff (MetaTime “Anchor” conjecture) to a conservative microscopic envelope forΓL via a coarse-grained multi-channel model with explicit Neff dependence, and identify muonic andhighly charged hydrogen-like systems as amplification targets.