Since Day 1 we have had the optional directory and the requirements of its own dependencies have not changed.
Since Day 1 we have had the ability to load and run ondemand, it just involved appsbrowser to load it and then run as if already installed.
OnDemand provides a simple shortcut, a single click from a flwm system menu to both load and run the application.
There is no fundamental change in how the optional directory is used or supported.