I use a hotkey to edit a foldername directly in the folder tree:
This works well, but the INLINE doesn't accept any of the parameters like
INLINE=end. Does it need to be written differently? Or can the feature be added?
Rename in the tree always selects the whole name by default, at least right now. The extra modes via arguments or Preferences / File Operations / Inline Rename only apply to the file display.
(Since folders don't have extensions, most of the extra modes don't really make sense, and pushing the right cursor will always put you at the end quickly. With a file you might want a distinction between the end of the stem and the end of the extension but that doesn't really matter for folders, which don't have them.)