Are there opportunities for formative assessment? Within the platform, Is there a way to retest a student's proficiency when the teacher has given additional instructional support in an area to then retest a student's understanding of missed concepts that are now secure?
Illustrative Mathematics provides several opportunities for formative assessment. This page provides a summary of formative and summative opportunities in the materials: https://learnzillion.com/resources/235863-monitoring-progress/
We currently do not have a formal way to "retest" a student's proficiency but thank you for the feedback. We will be sure to consider it when making updates to our platform.