It would be interesting to see the number and deployment rate of various Superchargers in the charts, like # of each version and maybe a graph…
The technical limitation is that charging speed is tied to a site and not a change. Any sites that are upgraded from V2 to V3 would have no good way to distinguish that they originally were V2. Even if this was manually coded (ie. all superchargers prior to 2019 are considered originally V2) it could be impossible in some cases to determine when they upgraded.
That said I do like the idea, but some data structures would need to be reworked to add in this functionality.
For the deployment rate of superchargers by location, this is coming via a feature addition detailed here: https://github.com/kdwink/supercharge.info/pull/49#issuecomment-665466733
Discussion of the feature here: Working on improved charts page