I have completed all the progressions of lizard crawl / climbing / squat, now what?
Although the progressions are chronological from easy to difficult, one exercise is actually not better than another. Even after mastering all of the progressions and months, it's recommended to include them in your workout schedules.
You can make the exercises or even mobility drills harder by adding weight with weighted vests, ankle weights, weight belts or dumbbells. You can also increase the repetitions above the set parameters to further make the exercise harder. Reducing the rest periods will also work.
However, adding weight or repetitions is rarely the best option. Instead of adding weight or repetitions, it's more valuable to focus on improving your form and using higher level principles such as slow tempo, control and mind-muscle connection.
After mastering all the exercises, you can also do 2-3 of them in one workout. For example, you could do bulgarian rows and behind the neck pull ups in the same workout.
Moreover, we still continue to do the mobility drills weekly in our training because they ensure our long-term success.