Interact with another mod?

Is it possible for Mod A to interact with Mod B? An example being my Large Smithy mod increases the storage limit of the smithy to 500. I’m making a Large Walls mod which provides behemoth and dinosaur sized walls. I have to add these walls to the regular smithy and the large smithy. Even though large smithy is a child of the regular smithy it doesn’t get the new engrams. So I need to be able to add those engrams to the large smithy in a compatible way. It being my own mod I assume I just go ahead and add it as additional engrams to large smithy and if it’s not installed it should be fine, right? Now what if it wasn’t my own mod; how would you go about this?