The Physics and Astronomy Department at a large, diverse, master's-granting university has recently implemented a pedagogy training course for graduate teaching assistants (GTAs). Using survey and interview testimonies from GTAs and other lab instructors over the course of three semesters, we identify potential areas of growth that can result from taking the pedagogy course. These areas include: developing a growth mindset and asset-based thinking, identifying the need for inclusive teaching practices, and implementing such practices. To help inform future pedagogy training courses, we have identified four personas that represent key archetypes of instructors that are likely to teach physics and astronomy labs. By cross-examining both sets of data, we have observed multiple areas that each persona is likely to develop as a result of training. We aim to use these results as evidence to further demonstrate the necessity for professional development for early career instructors.