There's only one gotcha with using the triggers that I found. May be different with a trigger on the amp, but I trigger the entire power bar, which means the amps are getting zero power until they get the trigger.
The gotcha is it takes the amp a couple of seconds to power up and begin playing sound.
For playing media like music, internet radio, podcasts, etc it's perfectly OK, I never notice the couple of seconds before it start. I did try and connect it to my Alexa devices, and that became super annoying - it would seem like Alexa wasn't even responding to me because the entire response might be in the couple of seconds before the amp was ready. So I updated the configuration on Alexa so that quick answers would come back to me directly through the device itself and only songs/media would be cast to the WiiM. That works fine.
But if you plan on using these speakers for a voice assistant scenario be aware that the power-up may mean the beginning of the response (or all of it) may be chopped off.
I don't know if it would be different using a trigger right in the amp. That's what happens with the trigger on a power bar the amp is plugged into.