I’m only just getting started with these. I’ve not found if the frequency can be increased on the official integration.
MQTT seems to report instantly on state changes.
You can also manipulate the frequency that the Shelly reports it’s status to the MQTT broker too. A little more config to setup some sensor devices to hold the status, but looks like it will work fine.I’ve not set it up yet though but there looks to be plenty of examples to follow here on the forum.
I can report back on my progress if you are interested.