Meta: The Issue may be too vague or may not use the "right" terms. Feel free to improve it and/or ask"

Need: It should be

• possible to generate more meaningful edit summaries
• easier to change the UI

This might be particularly relevant when Wikibase is used in Projects aside of Wikidata since they might need e.g. a different UI or different specialized API requests compared to Wikidata.

Problem: Some edits are usually small and generate a specific request, whereas others send a more complex and not atomic change that fully replaces several values on the backend. Partly this is also reflected in the UI.
The smaller or larger data that is seems seems to be done for concerns of request efficiency and/or the ability to generate more atomic edits and thus more specific edit summaries. Thus, currently, changes of the user interface seem easily to affect the request efficiency and the meaningfulness of edit summaries.

Solution: We should aim for decoupling UI, data that is changed and data which is actually send in a way that allows us to do changes to these more easily. I can only naively assume that this would require identifying changes and the source of the change "better", so that e.g. only data which is changed can be send or, vice-versa, several changes could be easily squashed to one request if that makes sense.

Related: T138748 (but for identifying data which is send back the the client)