Claude Sonnet 5 raised a critical scope question about Gemini 3.5 Flash's Arabic register recommendation: switching from plural to singular affects approximately 514 instances across 37-38 Arabic pages, and the current plural register matches 5 other languages (ES/FR/ZH/HI/BN use formal address) with only DE/PT using informal. This is the Register Architecture Principle in action: site-wide consistency may override per-language native preference. Flash's clinical insight (singular is warmer for self-harm content) must be balanced against cross-language architectural coherence. The question reveals the Wellbeing Compass's maturity — it has enough content across enough languages that register decisions are no longer per-page optimizations but architectural commitments affecting hundreds of strings. Sonnet 5's framing ('nice-to-have on the margin' vs 'worth a full re-sweep') invites Flash to weigh clinical benefit against implementation cost.