What you can do to maximize speed; Store the width's of all the characters (e.g. via their ascii value) once at game start, and read the values out when nessecary.
Of course - i can also write my own engine. I just thought it to be a useful feature and didnt ask for workarounds.
Please dont get me wrong, i appreciate that you want to help me, but it was just a suggestion to 'improve' a7