I've never had much luck with scenes. I know it's apparently the way to go and I know many use them, but I got frustrated a few years back and have never gone back. Maybe I need to go back to them and give them a shot, play with it some more. I've never been very successful with 3 way switches either. I had X10 switches, I've had Insteon for 8 to 10 years, have had the ISY, MobiLinc, Alexa - I work in IT and understand how most of it works, but have just had no luck with scenes. Not sure why - maybe I tried to make them too complicated, but seems I never got more than about half of the switches to come on or off when they should.
I get the delay and in fact with the program to get it to work and get most switches on I put one second between turning each one on or off and then I even have a loop and execute the program twice each time because I still get a switch or two that won't come on. I noted the house had been completely remodeled about 2 years back, complete new wiring as well. Before that I had aluminum wiring and the circuits were strung all over the house so maybe the new wiring will help me out and I should give it a shot. I've got about 24 switches and outlets, most of them several years old. I now have the new PLM and probably 5 switches that are dual band, the rest are all old single band switches. I've got 2 switches now that need to be replaced - they won't respond at the toggle at all and only sometimes to my program.