we are using LightWare SF20 / LW20 (Range finder) + PX4FLOW Optical Flow Camera Board without Sonar (Position hold), no GPS, we tuned the EK2_RNG_M_NSE. Both indoor and outdoor flying are fine. 9-inch propeller drone, 2.3kg. EK2_ALT_SOURCE still use Baro.
Worth understand the Understanding Altitude in ArduPilot.