Layered and legacy update will need to share some code, but some functions will have to be implemented differently. It will be safer and clearer if this is clearly represented by structs and interfaces. Pseudocode:

struct Daemon {
  someSharedMethods()
}
interface DaemonInterface {
  methodsLikeUpdate() 
}
LegacyDaemon implements DaemonInterface
LayeredDaemon implements DaemonInterface