Keyboard Maestro 10 Features in a Video

Okay so not all the features but at least this one feature I would really love to see in a video with an example.

Does anyone know of videos that explain subroutines and the details found here on this Wikipage?

I am really having a difficult time wrapping my head around this with out seeing some examples but no doubt it is really handy.

https://wiki.keyboardmaestro.com/Subroutines

In Keyboard Maestro, traditionally subroutines were implemented with the Execute a Macro action, passing a single parameter to the %TriggerValue% token, and returning results in instance or global variables.

In version 10.0, Keyboard Maestro adds an explicit Subroutine trigger which lets you specify the parameters by name, and whether the macro returns a value via the Return from Subroutine action. Such subroutines are called with the Execute a Subroutine action.

I would love to understand the added benefit of the subroutine added in version 10 of Keyboard Maestro. I have always just referenced another macro when I want things that I need to change in one location that is referenced by several other macros. Perhaps this has something to do with ascyrconous executions or something.