What does "it" here refer to ?

Hi~ I have some questions and would like to hear your opinions. Many Thanks~

My questions are as follows:

1. It seems that an objective is needed between “drill” and “deeper than”.

And I think that the objective is “The importance of meaning and relevance”.

2. What does “it” refer to? “The importance of meaning and relevance” OR the whole sentence?

3. In the last sentence, what do you think the subject “It” refer to?

“this model” OR “a highly effective platform” OR “deep learning” ? Which one could be the best in this context ?

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There are many tools that can assist leadership in making organizational meaning. (omitted) The establishment of clarity and meaning resulted in significant gains for all students and prestigious recognition such as the Broad Prize for excellence in urban education.

The importance of meaning and relevance makes it possible for stakeholders to drill deeper than organizational structures; it is a critical component of teaching and learning through curriculum and assessment. A. Z. shares an approach to personalized learning that provides teachers the framework to create instruction that is meaningful and relevant for their students and that builds on the brain research discussed

in the introductory chapter. It provides students the opportunity to make meaning, to build from prior connections, and to understand the relevance of their schoolwork to broader world connections. D.L.

describes the innovative Big Picture Schools model he established around the idea of providing students with the opportunity to explore their interests and cultivate their passions through real-life learning

experiences. He also shows that this model served as a highly effective platform for deep learning. It is the process of learning that is emphasized and transferred to future learning and real work experiences.