A dark theme for the flow, datasets, and recipe configs would go a long way toward making Dataiku fit into workflows that involve many other dark mode tools. Dataiku is definitely very bright when swapping from other tools which operate in dark mode. Extensions like Dark Reader do a pretty good job of generating dark mode for Dataiku, but native support would make it much prettier.
Here are some examples of how close to beautiful Dataiku already looks via Dark Reader. Just a little refinement beyond this could make it perfect.