Markdown with SVG images to InDesign?

Is there some reason why you're converting Markdown to docx? I mean, maybe I'm missing something, but you could go straight from Markdown to icml, and place the icml directly into InDesign. 

If your svg is dropping when you convert with pandoc, isn't that maybe a question for the pandoc maintainer(s)? I mean, I don't know if you can slip an svg into icml, but you certainly should probably be able to get an svg into a docx, and you're reporting that this doesn't work. 

XML looks like it would be two-way, but every xml export I try just generates an empty xml file.

Can you either describe your workflow here, or post a sample document? Because an empty XML file is not the expected export. I don't want to PEBCAK you, but you know, maybe the empty XML export is down to you not using InDesign's wonky XML tools correctly? 

From long familarity with InDesign, HTML/CSS, some XML and — regrettably — Markdown, I would say there's no way to get from Markdown to InDesign without a wholly custom code conversion project.

The only thing close to MD or HTML that InDesign imports is XML; I can't see any route here except a conversion from MD to XML This could be done in a number of ways including repetitous search-and-replace or GREP to convert one code structure at a time, along with some more sophisticated scripting in a macro-enabled text editor.

Maybe others here with deeper conversion and file structure experience have a better solution, but I think you are outlining one of the most nearly impossible conversions in the whole doc spectrum — simply because Markdown is a deliberately simplified tinker-toy approach to document structure, not really conforming to any standard but its own and forcing all but the most unimaginative, vanilla users to use what CSS elements will work, or elaborate, oddball combinations of its features.

I'm close to saying "forget it — rebuild the documents in InDesign from what text export and scrapes you can extract, and forget about any sort of conversion that preserves formatting, structrure, image placement, etc." Close but maybe not adamant.

(I use Doc360 for a client and have worked with other MD tools and environments, and think of it as something only a developer team could love, more "coding documents" than any kind of actual document tool. But it sounds like you've made the mistake of writing something very large and complex in it, and now need to get that project into a real doc platform. I hope someone here has better ideas than I do... 😛 )