Are you sure you want to change the default behaviour? [BTW you can drag the file tab to the end.]
Might it be preferable to have a keyboard shortcut that will move the file to the end? There might already be a command that does this, or someone might have already created this command
I'm happy to create either, but I won't be able to look at this til tomorrow evening (earliest) - someone else might give it a go in the meantime
"I'm here to save your life. But if I'm going to do that, I'll need total uninanonynymity." Me Myself & Irene.