The Daniel K. Inouye Solar Telescope (DKIST), formerly the Advanced Technology Solar Telescope (ATST), is now in its sixth year of construction. During the two years that have elapsed since our last systems engineering update we have been through factory acceptance of several major subsystems including the enclosure, telescope mount assembly, and the primary mirror. With these major milestones behind us, site assembly in progress, and with the integration, test, and commissioning phase about to begin, we will discuss what has been working well in terms of DKIST systems engineering processes along with some things we could have done better and would do differently if given another chance. The paper examines examples of successes including full-scale factory assembly of major mechanical components and some less optimum outcomes. We explore the reasons for success or failure, including the early delivery and level of detail in factory acceptance test procedures.