Welcome @MRBetes 
I don’t think you need the extra energy meter from Wallbox which they call Power Boost. I have updates coming in from Shelly EM every 1 second. Then use a Node-RED ‘Smooth’ node to process the readings. Every 10th reading it sends a payload with the average of the previous 10 readings. This provides a stable result which triggers a recalculation of the charging power - Up, Down or Sideways.
Glad to hear you’re using Node-RED rather than the scripting language in HA. It’s much easier to program. If you do decide to buy a Pulsar Plus, I think you’ll be very pleased with what you can do through this automation. My dashboard supports 2 options - Solar-only or Grid and it’s all I need.