Not sure if this has been suggested before, and apologies if it has. I currently have my two hybrid mods that share a lot of the same code, but I have to ship the code in each mod so that they can be installed individually without requiring one another. That means that if they update at different times, there is a possibility that one might break the other if they're loaded in the wrong order (such as if I change powertrain code in one, and the other one gets loaded first). It would be super useful if I could bundle all shared code into one "dependency" mod and have a way to specify the minimum version of the dependency that the main mods require. That way, if I update the dependency mod and then both hybrid mods, but the main mods get approved before the dependency (or some other similar situation), the game can delay updating the main mods until the newer version of the dependency mod gets approved. The game could also automatically subscribe to the dependency mods when subscribing to one that depends on it.
This is why the Nicelittle Parts Pack exists, lots of little mods, sharing parts and textures in one mod. It’s a lot easier to maintain as well since you only have to do it once, but if one something breaks, I might take a while to get noticed. Good ideas though