1. OnBoot is represented by a simple text file located at:
Use your favorite editor or base CLI editor vi to adjust.
2. OnDemand from the command line is as follows:
To add for example flpicsee use
$ ondemand flpicsee
To remove flpicsee use:
$ ondemand -r flpicsee
Looking at your PATH you will see ondemand as the last location. So often you will just need to call the program by extension name to invoke from on demand, Subsequent calls find the program eariler in the PATH.