Hi weirdcat
I have come across the same challenge in my short fiction, that challenge being that sometimes the ideas I would like to communicate are much easier done if I just come right out and say it, but feel it has more of an impact in a story.
I agree with Lakey and Ariel.Williams in that having a conflict between two characters, or your protagonist and certain circumstances, can be fertile ground for communicating your idea. This conflict can also be moved to another level, another place so to speak, where it can exist between the protagonist and the writer. A particular voice is required for this, and it won’t necessarily break down the fourth wall, at least not directly.
I find this allows me to psychologically construct the character in a particular way and then have him break away from this as much as the idea needs him to, without it seeming to be out of character for the protagonist.
I hope this makes sense.