Accessing animation notifies in a regular (non animation) blueprint

I built an asset which is a curtain using cloth simulation. The user can either open or close the curtain by hitting a key on the keyboard. There are only those 2 animations that I use and I send events from my level blueprint to my Curtain Blueprint which is a regular blueprint.

I want however prevent the user from retriggering the animation while it is playing

THIS DID NOT WORK:

My first idea was to set a boolean “CurtainActive” to true, start playing the animation and then setting it to false again. This was wrong thinking, as the events are non blocking, so what happens is that “CurtainActive” gets set to true, the animation is started and immediately set to false again, leading to the same behavior as before.

So I looked at animation notifies which would probablz give me the functionality I need, but now I saw that they work onlz from Animation blueprints which feels like overkill for accomplishing just opening and closing a simple curtain.

THE QUESTION REMAINS:
Is there a way to implement the behavior that I need using a simple regular blueprint or will I have to take the dive into animation blueprints to achieve what I want?