Official concrete information: We are actively working on this. This is challenging due to the fact that we are a fairly Unity-heavy team, and since becoming Ultraleap have been reevaluating our product strategy and tech stack as well as involved in recruitment efforts. Our goal is ultimately feature parity between Unity and Unreal.
The Unreal documentation being somewhat informal reflects a broader issue with our documentation experience, which is fragmented. We have a long-term plan for improving the documentation to bring it up to a higher standard of quality.