Question about intended use case for anim layer interface

I want to make a universal item animation blueprint that houses all of my item animations but does not require all to be loaded at a given time. I think anim layer interfaces would be useful for this, however, I am finding that these are not applicable to child animation blueprints which means I cannot just plug in a single state machine in the parent and then modify the animations for each state in the child blueprints and override the interface function. As a result, I am considering having a singular state machine and including five interface functions in my anim layer interface. This way each will control one of my five movement states (idle, idle + aiming, walking, walking + Aiming, and running) and the states can be altered by linking different ABPs (each of which can be loaded from soft references before activation). This will essentially mean I am making animation blueprints exclusively to store the 5 desired animations and nothing else and will have 5 anim layer interface functions in my main state machine. Is this an inappropriate use of anim layer interfaces? Will this be really inefficient? Is there a better way to incorporate layer interfaces?