This technical note treats recent work on quantum signatures of proper time in optical ion clocks as an external stress reference for the Clockability cluster. The note does not propose a new theory of time, nor does it interpret quantum optical clocks as confirming Clockability. Instead, it distinguishes proper-time accumulation, physical clock readout, trace comparability, and temporal exportability as separate descriptive levels. Optical ion clocks are analyzed as temporal interfaces: finite physical architectures through which proper-time signatures become accessible under specific conditions of state preparation, motional structure, coherence, and readout. The aim is diagnostic only: to clarify how high-precision quantum-clock regimes make visible the distinction between local proper-time dynamics and the operational availability of temporal order.
Danilo Tavella (2026) studied this question.