@Wayne-TP 

The FW reports up to date. 

Model: EP10

FW: 1.0.5 

HW: 1.0 

When I set "On" Duration to say 2 sec (or anything under 1 minute) and press Done it reverts to a 1-min delay.  I completely rebooted the device (held power button for > 10 seconds) to no avail.  Does the same thing.  Do I need a newer HW version (website shows up to 1.8?)  

  @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.

  @Wayne-TP

Version 3.3.800  Build 1666 

  @Wayne-TP 

BTW - I found this on Amazon which gave me hope that perhaps the HS105 was specifically designed for Momentary.  So I bought two and they behave the same way as the EP10.  Going to return them. 

  @Wayne-TP 

Thanks.  Turns out the Kasa is a little flaky with the momentary work around I came up with.  It will double press sometimes which depending on the device give me unwanted behavior.  For my gate and garage door a 'double' will stop the gate/door in its place.  If I can't see it I won't know what position it's in.

So I'm using Sonoff Smart Plugs for all my momentary functions.  It works great, down to 0.5 second delays, and is super easy to configure onto my network (the old Basic model was super hard to get onto my network).

I'll keep an eye out here if the Kasa folks figure out how to make theirs work.

  @Wayne-TP 

Looking forward to the update. Will keep an eye out.