Some update on this for those who may be interested. OikoLab is collaborating with Climate One Building this year for a major update of their weather files by using ERA5 parameters.
This addresses one of the weakness of cloud-cover-derived radiation values as discussed in this thread and above discussions, as well as using the latest weather data (up to end of 2020) to generate TMY files. We’re hoping that this will provide more consistency and transparency especially for locations outside of North America, and allow building-energy simulations to be performed using updated weather files that reflect the changing climate.
Thanks and please feel free to reach out for any questions!