There’s a Beta traditional characters version but almost no content in it. In the simplified version you can only choose to have traditional characters appear above the simplified ones like Japanese furigana.
The Pleco reader is a wonderful tool for advanced learners and even for native speakers reading, for instance, texts in classical Chinese: it’s so convenient to paste interesting text and then call up definitions from specialist dictionaries at the click of a button.
However for somewhat less advanced students I feel that text accompanied by audio is the high road of language learning. It’s just a shame that there seems to be a bit of a dearth of that in Chinese