Load and streaming hitch diagnosis

1. Mark the player action/region entry and capture Timing plus loadtime/file channels as needed.
2. Inspect Asset Loading Insights package order, async priorities, serialization, and Game-thread waits.
3. Correlate file IO, decompression, UObject creation, PostLoad, component registration, render/physics resource creation, PSO compile, and GC.
4. Determine whether work is synchronous, async but completed too late, or async followed by a blocking readiness phase.
5. Move/preload only the causal work, increase lead time, or amortize creation across frames.

Symptom	First evidence
first pickup/effect hitches	package load, component registration, PSO/decode readiness
entering region hitches	World Partition/cell activation, file IO, texture/Nanite demand
memory spike then GC hitch	transient allocations, object churn, retained load handles
asset says loaded but appears late	render/physics resource or PSO readiness
cold run hitches, warm run does not	OS/driver/cache-sensitive IO or compilation
async request still stalls	late request, completion on critical path, sync dependency inside PostLoad

Never “fix” by hiding the trace interval behind a shorter loading screen. If blocking is required, own it with a real loading transition and an explicit complete/timeout/failure contract.