While that works for most cases, when exporting the data to a spreadsheet, I don't get the reason from the comment box and then have to research each "excused" tag. Having the additional category fields would allow the exported spreadsheet to wok as it is, because you could tell the reason by code. There are times that I have absences that are excused and tardies are considered absences. Just think based on the way this module is organized, it might be easier to program additional categories than showing the comments.
The module is great as it is, but in the area of wishes and having applications for the additional categories, I was curious at how difficult it would be to increase the quantities of categories.
Honestly, I am not a programmer and have no idea how difficult it would be to make the changes.