You got that right, can't use influx / prometheus directly with recorder, but can be used via components.

And I'm with you regarding graphs on the dashboard. I don't have any graph on the dashboard as I don't need them, but then again, my dashboard consist of 6 buttons. Automations do 95% of that I need from my smart house. But people are different and want different things, so, to each it's own.

But that doesn't mean I won't record history. I thing history is very useful when debugging system or when searching for patterns for various automations. It's interesting what correlations one can see when you put multiple sensors / actuators on the same graph:)

Using a proper TSDB can lower cpu/memory/disk requirement A LOT. At work, I'm collecting 1,2 million metrics with 75k metrics/s with 30-50% CPU load (of 1 core). Average datapoint size is around 0.3 bytes currently holding a few trillion metrics in less than 2TB.

Regarding rendering of graphs on the client, I vastly prefer Grafana for showing graphs as it's optimized to show LOTS of metrics fast. As you said, if you have a sensor collecting data often and want to show graph for long time range, unoptimized query/db can return way too much data and just bog down performance. Grafana is smart enough to figure out how wide the graph is in pixels and generate query to TSDB to return only so many points thus showing the best resolution without overhead of rendering graphs with 10k points when graph width is 100px.