@josh gave an answer here, and yes auto-binding seems to stay a good practice in new pricing model
Question asked:
How does the WU system affect auto-binding? Since each keystroke attempts to save data to the server, will it be billed per keystroke per field?
Response:
We de-bounce auto-binding, meaning that we wait for the user to finish typing before updating the server.
So it counts as an item modified in the database (once, as other methods).
Another method could include a “Validate changes” button instead of auto-binding (if your users usually make a lot of changes on an item every time they modify it). But in my experience, for internal tools, the users usually modify one/two field(s) only when they work on something.