I have 33 devices (7 are virtual/simulated switches) and it seems ST is taking a lot longer to actually turn stuff on or off and get update notifications when I manually turn things off or on. It seemed much quicker when I only had 10-15 devices. I also noticed that I have a Lighting Smart App that turns several lights on when I get home at night. Sometimes not all of them will turn on.
Also when I run the Z-Wave Network Repair, it takes many hours to complete (like 10 hours). I’ll run it at night and according to my phone, will still be running in the morning. I’m not sure if I ever see that it says it completes, just eventually it is back on the previous screen instead of saying Z-Wave network repair started.