Just bite the bullet and build a platform level capability to support user templating similar to React. I don’t mean be like React specifically, or that complex really; I mean any kind of template syntax that makes it relatively easy layout the page and components and very simple theming with a high level syntax.
This would be a ridiculous and unnecessarily flexible feature for most sites, but this is a a developer site. People would love it and use it.
They wouldn’t even have to know the syntax, because they could just browse and copy an existing well designed and refined template from the ecosystem that would instantly appear without even any official support.