Hey @scotjock81 ,
you can stay connected to everything in your life by making use of 2 SIM cards in the S21 range with the Hybrid SIM slot.
@scotjock81 , All the S21 range will take either two nano-SIMs; or one nano-SIM and one eSIM.
DylGMD was fairly close about the physical SIM setup being double-sided, but you shouldn't need another SIM tray or to reflash etc. I pulled this from an S21 series User Manual:
Hope that helps! 🙂