Yes, on any programmable layers (offline 1, 2, 3 ), you can keep the original function of the key BUT when you do Fn+Key, then the Media and HotKey function is triggered.

You can visit here and download the manual  to have a look on them,  then you will know how to use it.

If you still don't know how to use the "FnX" function, please leave message here, probably we can make a video to show how to use it.

With the software, i see that you can change the function of a key and assign a Media function or a HotKey function. When you do that, the key do not anymore have it's original function.

I am trying to know if there is a way to keep the original function of the key BUT when you do Fn+Key, then the Media and HotKey function is triggered.

Example: I want to have Fn+C launch the calculator. Or Fn+P to have the Media Play function.

That should be possible. There are keys that have no function assigned by default. We should be able to define our own Fn+Key with the function we want from Media, Hotkey and Macro.