Discussion and dependency boundary

problems. The unrestricted channel-support question is not left open: Theorem thm:anysupport realizes every support family. Remaining restrictions worth studying include subsystem realizability with prescribed branch support, geometric locality, and resource constraints. Continuous-variable and thermodynamic records require an infinite-dimensional domain and convergence theory absent here. Higher-order protocols require an explicit higher-order type and composition system, rather than being obtained by renaming a CPTP access channel. No result in the supplied distributional or gravitational comparison material supplies these missing structures.