Use variables in an action to sync attributes with zha_toolkit

Hi all. I have a Zen thermostat that I have not deployed yet because I cant seem to set the max and min set_point temperatures for cooling (they show up with sliders for heat).

Im trying to write an automation so i can use zha_toolkit to write the values to the thermostats hidden attributes when the heat max or min set_points change. (Ill settle for using the set_points for heat for cool as well)

the automation triggers correctly when the sensor has a change but I cant seem to read that value and use it in my action

Heres what I have in my automation right now.

alias: sync max temps
description: ""
triggers:
  - trigger: state
    entity_id:
      - sensor.heat_max
      - sensor.heat_min
conditions: []
actions:
  - variables:
      temp_c: "1900"
      set_temp_c: {{ sensor.heat_max | float }}
  - action: persistent_notification.create
    metadata: {}
    data:
      message: max changed {{ set_temp_c }} c
mode: single

set_temp_c: "{{ states('sensor.heat_max') | float }}"