I have similar process setup as original poster, instead of MQTT, I use home assistant Node-RED pallete which exposes all home assistant entities to nodered.

Node-RED automation is SO much better than home assistant automation or Huggins, ability to deploy modified flows when nodes on same flow are kept running is AMAZING!, makes dev cycle so much faster.

I use home assistant's builtin zwave, homekit controller, homekit bridge, Sonos, and InfluxDB, everything else is commented out. It's all running on used $50 HP Prodesk G2 with Ubuntu server with HASSOS in VM, VS.Code server in docker. Uses about 7 watts/hr.

I use it with HomeAssistant. I like HA automations for many things, but I really prefer NodeRed for gluing together systems or sketching things.