@Edent I worked on this project few month ago https://github.com/Conserto/GreenTrackR
It's not technically oriented so there is no advice to mitigate issues but it take into account data suck as the server location from https://app.electricitymaps.com/map/72h/hourly and others stuff.
Sadly I don't have time to work on it anymore to add firefox support, CLI integration, …