I guess you could try adding ‘homeassistant.components.mqtt: debug’ under the logger component to see the topics that are being published by your blind controllers. This might help find out the state topics. If the controllers do subscribe to their state topics, you can add an automation triggered at HomeAssistant start event to publish a topic requesting for the state, something that looks like this -
alias: “Power state on HA start-up”
trigger:
platform: homeassistant
event: start
action: