Found how to solve an issue I was having with MQTT / HA this morning. It may have helped with your Omnistat issue and values.
Now it's too late as it is not working these days.
Here have been configuring (reconfiguring) my 1-Wire network to using MQTT.
I currently have set up two main 1-Wire hubs for temperature only DS18B20 sensors. I can go up to 5 sensors per device.
I was not getting temperature readings from one hub here and using MQTT explorer noticed that the MQTT was not working for one hub.
Using MQTT explorer deleted the hub and let it recreate the broadcasts and now it is reading the hub correctly.