MQTT Themostats and Switches

I am working on an MQTT integration between my RV’s control system and HA. I have a couple of questions:

  1. I have a couple of switches that control things besides lights. For example, one controls vents. Those vents are UP or DOWN. Is it possible to specify through MQTT Autodiscovery that the Switch is UP/DOWN not ON/OFF? For clarity, I am not talking about the command that is sent via MQTT, I undestand that. I am talking about the way it is shown in the HA interface.

  2. I am setting up an MQTT thermostat and my RV has an AC Unit that has Cool and Heat modes and also has a furnace. They are both controlled through the same setpoint command. My idea is to setup the furnace using the aux_command_topic and aux_command_state for auxiliary heating. What I cannot find is what value is HA expecting in those topics. Does it see auxiliary heat as on ON/OFF command or is it a mode like the mode_state and mode_commands (ie. heat, cool, off)?