@Rhyono yep that is definitely it.
The other library errors I was getting turned out to be just me being rusty and messing up the syntax while converting away from LibStub (used ':' instead of '.' as a constructor between the global library table and the function definition, adding an extra 'self' variable to them all and throwing off the values. DOH!
@sirinsidiator you were correct, dependency checking had nothing to do with it!