I am a novice with MidJourney. I just got lucky and saw someone use the prompt with Spritesheet in it. As it turns out that word works magic in MidJourney. I happen to have mediocre skills in photoshop. I would just try spritesheet the next time you want to do something with MidJourney. I started looking into shaders lately and a friend of mine showed me some cool tricks that really helped get me started in that path. That is how I do most my effects was with shaders.
I have to right callbacks as well, but I think the trick is to create a struct or class that holds the inputs. Then you feed those results into that struct/class and then pass that around to the classes that need to access the inputs. That way you abstract all that input stuff away and pretty much keep it to one or two .cs files. I do enjoy the new input system more then the old one. Though I did find a quirk with the new system and WebGL builds. The Controller 2D Vector Composite does not work with the up and down. I had to split it to 2 1D axis instead and combine it in script to make it work. That and invert the Up and Down. Go figure... hopefully the LTS fixes it.