Unity URP vs. Unreal Engine (OpenXR): Which Is Truly Better for Meta Quest 3 & Standalone VR in 2026?

Comprehensive 2026 systems engineering audit comparing Unity URP and Unreal Engine 5 for Meta Quest 3 standalone VR development. This technical paper analyzes mobile silicon thermal envelopes, the Qualcomm Snapdragon XR2 Gen 2 SoC, draw call budgets, battery discharge kinetics, Tile-Based Deferred Rendering (TBDR) pipelines, and OpenXR runtime benchmarks. It evaluates physical frame budget constraints (11.11 ms for locked 90 FPS vs. 13.88 ms for 72 FPS), Dynamic Voltage and Frequency Scaling (DVFS), and memory bandwidth bottlenecks across mobile heterogeneous architectures.