The LDML spec has grown unwieldy over time. See for example

I suggest that we put together a plan for moving to a topic-based approach, where each major topic is in a separate webpage. It would result in many more spec parts, but would allow for each one to be more self-contained.

This could be done incrementally over time. For example, we could create a new Units Part, and move all the text having to do with Units into that Part. To make this easier, we might consider giving up on maintaining old links.