@kjr Good! We have several users using it with r2l and bidirectional text happily. Here's the config setting:
https://prodi.gy/docs/install#config 
Installation & Setup · Prodigy · An annotation tool for AI, Machine Learning & NLP
A downloadable annotation tool for NLP and computer vision tasks such as named entity recognition, text classification, object detection, image segmentation, A/B evaluation and more.
Matthew Honnibal