Sorry, that took a while.
I’d like to have capitalization turned off for the file name only.
If I change the keyboard, it’ll be global, and also affect the edit box the same way.
So, file name: No initial cap by default. (because the desktop keyboards are dumb and don’t auto-capitalize.)
Document: Whatever the users keyboard wants, for convenience.
I assume you can provide hints to the keyboard in the text box to not capitalize the first letter, on a per-field basis. (password, numbers, credit card bits, hide the characters, etc).