In "Starting Directory" at "Windows Terminal General Profile Setting" https://github.com/MicrosoftDocs/terminal/blob/main/TerminalDocs/customize-settings/profile-general.md#starting-directory, its written that it's optional to specify startingDirectory and it will default to %USERPROFILE%, however, the latter then notes

When the startingDirectory value is not specified, you will get different results depending on where you launch Terminal:

I find it a bit confusing as the behavior is actually like this:

• startingDirectory unset: %USERPROFILE%
• startingDirectory explicitly set to null: Arbitrary working directory written there.

So the documentation doesn't write any distinction between "unset" and "null". Thus, my suggestion is either have another example which tells that setting startingDirectory to null will use the program working directory. Additionally, the above quoted text may be replaced with:

When the startingDirectory is explicity set to null, you will get different results depending on where you launch Terminal:

I'm not good at wording it, but the point is the documentation doesn't differentiate between not specifying a field vs. explicitly setting the field to null.