Hi @robertjuric ,
as you're particularly interested in MQTT for logging through influx and grafana, that is exactly what I've been doing so this might be of help.
My project did not exactly use MySensors, but I'm interested to get MySensors to work on the rest of my raspberry py, database and dashboard environment.
The raspberry pi has a python script running an influx client here : https://github.com/nRFMesh/nRF52_Mesh/tree/master/raspi/influx
That client collects MQTT topics and forward them to the database.
some example dashboards are shared here that show how influx queries are written in grafana, also to make hour averages: https://github.com/nRFMesh/nRF52_Mesh/tree/master/raspi/grafana
I do recommend keeping as many things running on the raspberry pi as possible, e.g. MQTT broquer, scripts, services, as linux is an advanced operating system that makes logging and debugging of errors much easier than running on a microcontroller.
I'm not sure how much what I shared is relevant to you, but in case you're interested or have questions, just let me know.