Fable 5 Crashed My Subagents. The Fix Was the Cheaper Setup. (opens in new tab)

TL;DR for builders I ran Claude Fable 5 over a free-window weekend to rebrand six live sites on one design system. The lesson is a routing one: Fable 5 (about 2x Opus 4.8 per token) earns its price on judgment: the design system, the token structure, the calls the rest of the build inherits. Route the routine propagation to a cheaper model. I pinned subagents to Opus 4.8. Running Fable as the session model crashed my parallel subagent fan-outs. Pinning the subagents fixed the crash and happen...