Hi,
nor does there seem to be a way to
have every instance of the blueprint
have a unique reference.
click on the “eye” icon next to a blueprint variable. Then you can check expose on spawn and it will be exposed on spawn (your constructor in the trigger) and you can also set it inside the editor (e. g. create a variable of array of action objects inside your trigger and then populate that array inside the editor) or do it in the level blueprint as described in the answer above.