I did try the javascript bit in the past when it got released, but I found the interface more sluggish so I stopped using it.
I haven’t restarted my HA docker until today when I updated to 0.67.0. I tried changing the javascript version I use but that had no affect. Still seeing most of what I reported above with the exception of the “null - null” issue being fixed previously. I don’t get why the chart shows 3 data points for 2 values. 2 of those data points will always be the same and then the are under one of them is filled green. The 2 additional °F as was pointed out previously are for Auto or Eco modes. However, they shouldn’t be showing while in heat or cool mode as they functionally do nothing in those modes and can be confusing too.
For the charts I believe you have 3 data sources
The target temperature for warm, the target temperature for cool, and the actual temperature?
No. it shows up on the chart when I hover over them as: target, current temperature, and heating. current temperature and heating are always the same and heating is the one that is green and shaded