Standard double-slit and interferometer experiments treat apparatus geometry, boundary conditions, coherence, detector response, and which-path distinguishability as sufficient variables for predicting interference visibility. This paper preserves that standard quantum-optical null model as the baseline and asks a narrower residual question: whether a dynamically reconfigured two-path apparatus can show visibility dependence on the time at which the relevant apparatus context becomes locally available. The proposed apparatus-context hypothesis is intentionally carrier-neutral. It may be represented inside the broader space-cell program either by deformation-like geometry, stress, shear, or topology variables, or by an extrinsic scalar χ-like compression/event-density coordinate. The first experimental question is not which internal carrier is correct. It is whether any additional finite-speed apparatus-context variable is required after ordinary quantum-optical effects are modeled and controlled. The primary observable is residual visibility as a function of reconstructed apparatus-context delay, Δ_ctx = τ_interaction − τ_context available. Under this sign convention, Δ_ctx < 0 means the photon-apparatus interaction occurs before the relevant two-path context has become available, while Δ_ctx > 0 means the context is available before interaction. The proposed support signature is a reproducible negative residual in the negative-Δ_ctx timing window, absent in sham-switch, one-path, decoherence, detector-angle, path-phase, material, and deformation-only controls. The proposed experiment reflects findings from toy-model interaction/accounting tests and design-translation results. These simulations sharpen criteria for a falsifiable experiment, define controls, and translate the timing variable into implementable design constraints.