We've previously seen compact Rockchip RK3399 powered single board computer with support for dual displays with the likes of Rock Pi 4 and NanoPi M4B thanks to HDMI and MIPI DSI interfaces.
Novasom M9 is another compact RK3399 SBC with both HDMI and MIPI DSI, as well as DisplayPort or embedded DisplayPort (eDP) for a wider choice of display interfaces, although as I understand it is still limited to dual independent display configurations. Another differentiating feature is the option for a wider -20 to +85°C operating temperature meaning it can be equipped with Rockchip RK3399K processor instead of RK3399,