According to
https://switchbrew.org/wiki/Flash_Filesystem#System_Savegames, the save game for title ID 0x80000000000000F0 (pdm:/) holds the "Play Data log", and 0x8000000000000041 holds "Home menu icondata/lru list for recently played games." Together these make up the play activity and allow the switch to display icons for each of the titles. This could be backed up and restored easily, but they're tied to a user account, so would need to be modified to the current user account.