Microdata doesn't need to _fully_ describe something. It's not describing to a machine how to perform the recipe, it's just annotating the text with useful metadata. It's metadata, doesn't need to be full data.
To me, it sounds like you want to annotate data that doesn't even exist.
I also haven’t seen a site that actually turns that into a neat visualisation, but as an amateur chef, properly timing steps of a recipe is definitely important.
I’m inclined to agree with GP though that a good model should be able to capture that.
You can then _decide_ what to paralellize (maybe you want to take it slow, maybe you have another person to help you, etc).
To me, it sounds way simpler. Specially for those writing or annotating the recipes. You're thinking of the reader, but the writing is important too, it's the hidden cost of making super detailed models.