I have been using the Harmony hubs on some jobs for a couple of years and one needs a separate trigger for a power amp that isn't used often- the old AVR had the ability to assign the triggers to Main or Zone 2, which was perfect because we weren't using Zone 2 for any AV functions and that let me assign the commands I needed- House ON, House OFF, LivRm ON, LivRm OFF and ALL OFF. I bought a Lutron Caseta switch with Smart Bridge and Pico last week and have been playing with it- the switch works perfectly and I can assign buttons on the remote for it, to turn ON, OFF and use the +/- buttons to dim it. Next step is to get a lamp module and assign it to the LivRm ON/OFF buttons, which can be re-named, too.
This module and Smart Bridge also allows me to add commands to control their Caseta light scene control switches and if I needed another 12V trigger, I could add a lamp module and plug a 12V wall wart into it.
I have read that the WEMO smart switch works with the Harmony hub- I can verify that the TP Link module doesn't, although I read that it can, if additional steps are used but I need it to happen more quickly, it needs to be very reliable and I don't want to make them walk through multiple apps to get everything to work. That's a good way to make people lose interest in using the system.