Passing value from dashboard via MQTT

In setting up HA - via MQTT - to control a self-made HVAC (Rasp Pico_W / Micropython), I have some progress to get HA to read/ present temp sensor_data on the dashboard and switches to control settings of my HVAC.
The next step is to set the target temperature of the defined HVAC zones. So I added a thermostat tile to the dashboard with a heating ON / OFF switch, the current zone temperature plus the target temperature.
I got the zone’s existing temperature visualized using the yaml conf below but I do not see how to properly organize to get to inform my HVAC of an ON/OFF change and a temperature(change) for a specific zone. Like { “zone”: “ON” } and { " zone": 21,5 }

The yaml data below allows me propagate the temperature I set in the dashboard (however, it seems to lag one temperature adjustment. If I change from 20 to 20.5 and 21, the HVAC receives 20.5; the change thereafter gives me 21.)

  climate:
    - name: Heating_zone_woonkamer
      unique_id: Heating_zone_woonk
      icon: mdi:radiator
      temp_step: 0.5
      current_temperature_topic: heating/sensor_data
      current_temperature_template: '{{ value_json.sl_woonk }}'
      temperature_command_topic: heating/control
      temperature_command_template: '{{states.climate.heating_zone_woonkamer.attributes.temperature }}'
      modes: ['heat', 'off']

To work on the status of a switch, I could use: payload_on: ‘{“suspend”: “ON”}’. But I cannot work out the transition from the switch to the settings of a climate / temperature control. Guidance is highly appreciated.
Thx !