Greetings,
Some research and hacking this morning has allowed me to create a script to read sensor values from an Alen BreatheSmart air purifier and publish them for HA via MQTT. These purifiers are based on the Tuya IoT platform and publish a reading for air quality (PM2.5 in micrograms per cubic meter), its fan speed, and its remaining sensor life along with some less-interesting data.
If you have one of these filters and are interested, please visit https://github.com/dlarrick/alen-mqtt