Available Studio Data Widgets

System

We would like to add additional attributes to vocab nodes in Metatagger Studio. We will use these in downstream applications (not Interwoven) but need to maintain them with the vocab terms themselves which are maintained in Studio. We can add additional elements in the <schema> block of metatagger_studio.cfg; however, the widgets available are limited ("textfield", "textarea", "uref", "trainSet") and seem to be missing some basic entry types (like checkbox, radio buttons, drop-down list, etc.)

Are there any additional widgets available? Can't find any documentation on this.