It is true there is a way to add a global class, but I do not see that it is fine grained enough.
As an example:
I have a product with a dropdown choice of number of names and a cost associated with the number of names. So say it shows in the dropdown as 2($2). There is a class associated with the total option (option plus price) but not for class=”option” class=”price” if you want to create a space between the number and price, you can’t as they are both included in class=”option”.