Function pooled 

pub fn pooled(label: &str) -> bool

The transients a backend pool owns; everything else the graph declares transient stays backend-owned. One set for every backend, because which labels are pooled is policy rather than a per-backend capability: a set that differed per backend would make their footprints incomparable and would leave the soundness sweep below checking a grouping no backend builds.

gbuffer_depth is deliberately absent while its three colour siblings are here. D3D12 creates a shader-readable depth target with a typeless resource format (R32_TYPELESS) and views it as D32_FLOAT / R32_FLOAT, while PixelFormat::Depth32Float names one format for all three roles, so the pool would create a resource the feature’s SRV cannot view. Pooling it would reclaim nothing anyway: its one-pass planning lifetime is an artifact of a graph that cannot model the upscaler (see the_prepass_depth_is_short_lived_only_in_the_planning_graph).