@OVNI 

I figured out how to create a momentary function (ON-WAIT-OFF) using an ON/OFF Device (Smart Plug) by creating a Scene.  I created a (Momentary) Scene where I turn a Device (Smart Plug) ON, have it held ON for 1-second, then turn the Device back OFF using the Smart Menu/Scenes Tab.  Once created the Scene shows up at the top of the Home Page above the Devices of the Kasa App which was perfect since I wanted one place/menu where with one click/tap I could perform an action without going to another menu. To execute the momentary function one has to click/tap the Momentary Scene that was just created.

The fact that the Device I'm using for a momentary also appears on the Home page is undesirable. I do not want to ever accidentally turn that Device ON and forget to turn it OFF nor have someone else not know better.  Equipment that use momentary switches do not usually want to see the momentary switch continuously CLOSED (or OPEN depending on design) or else it could cause erratic behavior and sometimes damage. 

I had to do this for both the EP10 and the HS105 in order to create a momentary switch.