Cerys looks like such a great mod! It's been a part of my current play through, and I was just about to launch from Fulgora to Cerys when the v1 updates got released.
After version 0.9.9 there is an incompatibility that prevents the game from loading when also playing with Productivity Research For Everyone (https://mods.factorio.com/mod/ProductivityResearchForEveryone). So I need to decide which mod to continue on with.
I feel like it's a long shot to chase down every possible issue, but thought I'd ask to see if it might be fixable on this side?
I did bring up the issue on the other mod author's discussion forum, to see if it's possible to fix on that side. https://mods.factorio.com/mod/ProductivityResearchForEveryone/discussion/6794d16054b6c7d95ca621f7
Either way, this looks awesome and I look forward to playing through the content you've created eventually!