Works via inline source blocks in org-mode. You can evaluate them and turn them into png/svg with org-babel evaluation.
I find the indentation of the source doesn't work too great in source blocks.
Deployment diagrams seem like the most expressive diagram type for what I want.
It works pretty good, but embedding images is a bit limited. https://crashedmind.github.io/PlantUMLHitchhikersGuide/PlantUMLSpriteLibraries/plantuml_sprites.html
I actually kind of like the style - it's just kind of goofy.