how to properly test 2GIG smoke detectors

I prefer canned smoke, but you can use other means… You should test your smokes monthly.

In my case, I added a 100db zwave siren to my system’s third floor sleeping area

That’s a great example of testing and a very important topic. I think many people don’t test at all and very few use canned smoke. The test button on the smoke detector only tests the electronics but not the smoke sensor. Canned smoke tests the whole thing.