Here is a streaming mixer designed for serious pros in mind. The Roland VR-6HD is an audio/video mixer with direct streaming encoders. It has 6 HDMI inputs and 3 HDMI outputs (plus USB-C). It supports simultaneous dual streaming via USB/LAN. You can record streams directly to a SDXC card.
The VR-6HD is compatible with iPad, macOS and Windows. It offers PTZ control for up to 6 cameras. It has a 4.3-inch touchscreen display and serves as a 28-inchannel digital audio mixer.