+1. Would love this capability, especially since it's pretty confusing for some of my not-so-tech-savvy clients who get very confused when they try to add a new tag in a frontend submission form.
+1 for this as well. We are finding it is very confusing to our clients as well. It seems like a reasonable request when so many other WP form plugins have this capability. We really do not want to have to use another plugin to be able to achieve this.