One thing that could be useful is to display the resolved environment when --python auto is used (or maybe even every time regardless?), just to validate the result is as expected. Something like a log message Resolved Python: [/abs/path/to/python] before the package tree listing would do the trick.
Describe the feature
Referenced from https://github.com/tox-dev/pipdeptree/issues/362#issuecomment-2123099417 (adding it here so that we can track it):