My son has a Catrike Max and I own a HP Velotechnik Scorpion+ FS26 . We both have left and right Mirrycle mirrors on our recumbent trikes. I rode many years with only a left mirror. But 2 years ago, I added the right mirror and I'm so glad I did. My rear vision has improved with the second mirror and I convinced my son to add a second mirror when he bought his Catrike Max this past year. Great tutorial on mounting the Mirrycle mirror! I enjoy watching your RU-vid channel.
I use mirrors on both the right and left. I cycle to a university every weekday and that extra mirror on the right helps me keep track of pedestrians walking around the campus. Thank you, Utah Trike, for all you do. If it weren't for my trike cycling would be impossible.
I strongly second Utah Trikes' recommendation to get a mirror if you don't have one. My Catrike Villager came standard with a left-side Mirrycle mirror, I soon added another Mirrycle for the right handlebar, so I now have great vision to both sides in the rear. Although I no longer do much street riding, I find the mirror very useful for just riding on bike paths. I also highly recommend getting a raised flag or pennant for visibility by cars when riding on the street.
I find a mirror mounted on cycling glasses to be the superior solution. With just a small tilt of the head you get a panoramic view behind you. A MUST if you ride recumbent.