Sorry this is taking so long to port over to OMV4 but my time on this is very limited and there is a heck of a lot of code that needs to be converted.
So far I have a working plugin for CPU temps only. I still need to figure out how to add the extra sub panels, the code (below) was working for OMV3 but I just can't figure out why it is not working under OMV4. I don't want to move on to the other sensors until I have gotten the sub tabs working.
Code