Emporia team, here’s another idea: partner with the Home Assistant team. The recent addition of a full energy usage and monitoring stack in HA means that a whole new audience of hobbyists will now be interested in adding energy monitoring. As disappointing as it seems that you will not be releasing a local API, what about building a native cloud integration with HA?
Work with them to build a supported integration with Energy Monitor and Utility Connect. Advertise it as “Home Assistant” compatible. Get added to their list of supported integrations. The home automation industry is growing massively and HA is the “go to” solution for the serious hobbyist – leverage that community to spread the good will for the Emporia products.
Yes, please consider adding extensibility to the system via APIs!
Maybe as an even easier and quicker option for your development team would be to open up access to the raw data on your cloud server so we can build our own interfaces (like a local node that polls the cloud server data) so we can build integrations into SmartThings/Home Assistant/Hubitat.