A fresh install of B4 (and probably B3, but I can't check) has the close icon on the file tabs (the toolbar tabs, not the window tabs). If you go into options and turn the close icon off, the text is re-arranged centrally to each tab. Enabling the option 'abbreviate file tab captions' reduces the size of .h tab text to just .h, but the tab stays the same width.
If you now untick 'abbreviate file tab captions' the .h changes back to the full filename as expected, but the tabs are now slimmed down to the width of the text. Re-enabling 'abbreviate file tab captions' now correctly reduces the shortened tabs to just the width of the .h text.
