Create a market (even one no data provider covers), get a full liquidity curve from the real HFP engine, then push in-play events and watch the price react instantly.
Tier C/D markets get wide spreads and tight risk caps automatically — that's the engine protecting itself when it's blind.
"What's the price for MY size?" — walks the ladder, returns a binding average price.
⚠️ Big queries are themselves signal — ask for $500K and watch the engine's sharp-flow score (and the next quote) react.