I had a thought about a possible way of spacing glyphs in a fillable field to emulate tracking. Combs just don't cut it, way too crude for what I do. Would it be possible to write a script that would add a space between each pair of characters typed, and use a factor, like 2x to modify the horizontally width of each space? Ideally, the formula could use both fractions and integers for horizontal scaling, e.g., 1/5 width, 5x width, etc. As the designer, all you'd have to do is change the value to increase/decrease the tracking in the field. What do you think?