You might be tempted to have a threshold for documentation, meaning “when they re-labeled that field for us from Customer to Client, no big deal” and skip noting this in your log but don’t skip it!

Especially since everything is essentially a “version 1”, you need to have a log in case there is ever a cascade of problems, only evidenced if you document the evidence.

If you don’t want to clutter up an official document, perhaps coded and sent/reviewed by accounting, then keep a “small updates” list so you can see what is happening over time in your project.

You will be glad to have the data when it’s needed and at the end of your project to show where the extra time was spent.