"A new approach, which the classes have already begun to adopt, is bringing more students in but dividing them into groups of six to eight. Each of those groups will work with their own volunteer trainer, and they’ll move at their own pace."

If the goal is to scale small group in-person instruction, why not use Open Systems Instruction? This seems like the perfect use case. The book Public Schools Should Learn To Ski describes the benefits really well, but I'm sure there are other books on this.