I made a C# file with three MonoBehaviours in it: a base class and two that inherit from the base. When I tried to attach one to a game object in the Editor, the only one that appeared in the list of components was the base class. When I created a separate C# file for each of the child classes, then they appeared in the components list.
It’s not a big deal. I’m just wondering if it’s possible to have multiple MonoBehaviours in the same C# file for convenience.