July 3rd Update:
Now compatible with ECR
Small touch ups to vanilla OWB

peak mod :3

For some strange reason, you only need this submod for Monarchs & Margaritas and any expansion submods beyond that. I cannot figure out why this is, despite the fact that ECR & RR use the same province map, it needs a patch at a certain point. When I use my own submod for playthroughs, I only turn on this compatibility patch for when I have the entire map filled out, but usually I don't go past RR for lag reasons anyway.

Long story short, I listed the main expansion submods for clarity, but you can use this submod as I described above. Considering that this compatibility submod is for such a niche of players in the community, I didn't see it necessary to elaborate on these specifics, until now at least. To answer your question, @Zam138, the mod is fine as-is, I was just slightly burnt-out when I got to this phase and just did it a weird way like this.

Very keen eye, I was wondering if anyone would pick up on this.

So, on Steam it says this mod requires all of the map mods, but it only lists OWB, Old World Roads, and Monarchs and Margaritas in the descriptor.mod file, which I've come to believe means it only will overwrite those three mods, rather than every mod listen here on the workshop. Is this an oversight, or is this mod fine as-is?