Marsha Kramer (Margaret) passed away on January 23, 2020, a day after this episode aired. This was her final performance.
The story line of the elderly man who used to live at Mitch and Cam's house showing up and wanting to pass away there is similar to a story line in an episode of King Of The Hill. In season 9, episode 2 titled 'Mrs. Wakefield', the former owner of the Hills' house shows up and causes a stir when she repeatedly attempts to enter the Hills' house so she can pass away there.
Luke, Lily and Dylan are all absent in it. It's Luke's last absence, Alex's last was in the previous.
When Phil asks Clare to help him get out of going into space she says 'fine, but if I do this you're not allowed to quote Star Wars to me anymore'. Phil then says 'I love you' to which Clare replies 'I know'. The is what Princess Leia and Han Solo said to each other in Star Wars Episode IV A New Hope.