This is a recording of a Meeting-in-a-Meeting (MiM) titled "Supermassive Black Hole Studies with the Legacy Survey of Space and Time" held on 2020 June 1-3 as part of the 236th Meeting of the American Astronomical Society. The MiM was organized by the Rubin Observatory Legacy Survey of Space and Time (LSST) Active Galactic Nuclei (AGN) Science Collaboration. There were 6 sessions making up this MiM, and this is session 6 of 6. The MiM had a total of 16 talks plus a discussion session. There is one talk and one discussion session with talk titles and speakers as follows: AGN Reverberation Mapping with LSST and 4MOST TiDES: Black-Hole Masses, Cosmology, and Binary Black Holes - Sebastian Hoenig (Univ of Southampton) Discussion Session - largely focused on LSST observing "metrics" for AGN science and future meetings of the AGN Science Collaboration Please refer to the other recorded sessions for the other talks. Each talk is about 20 min long with 10 additional min for questions/discussion. Some more details about the LSST AGN Science Collaboration and related topics can be found at https://agn.science.lsst.org/ The YouTube links for the 6 MiM sessions are the following: Session 1: • Supermassive Black Hole Studies with the L... Session 2: • Supermassive Black Hole Studies with the L... Session 3: • Supermassive Black Hole Studies with the L... Session 4: • Supermassive Black Hole Studies with the L... Session 5: • Supermassive Black Hole Studies with the L... Session 6: • Supermassive Black Hole Studies with the L...