its very common gesture for when logging in to any famous sites like gmail or facebook to
to have this 4 quick steps:
1. Type Username
2. press TAB key
3. type password
4. ENTER key
Thats very quick and your finger muscles are already accustomed to it.
But in xenforo,
you need to press TAB twice to get into password box.
i suggest to have it change to standard quick access
username TAB password ENTER
for users quicky experience