From the bug report , which also has a screen shot mock up "This would make it easier to identify the folders of diffrent mail accounts. This would also make sense for the top account nodes."
Your issues will best be addressed in support - please post at https://support.mozilla.org/en-US/questions/thunderbird-android. I'm confident most of them can be resolved.
Update - in the mobile plan for 2026, not yet released, we plan to do some exploration of this idea. So there may not be code released, but there will be an evaluation.
https://addons.thunderbird.net/thunderbird/addon/f9-hides-the-folder-pane/ provides a key.https://addons.thunderbird.net/en-US/thunderbird/addon/folder-pane-toggler/ provides a button.I have used the key in the past.
