Are there any limitations from the Home+ app that illumination can't use certain functions over QS?
The main differentiator between the Lutron Home Control + App with Homework's QS and Homework's Illumination is that Illumination does not support the Remote Access feature. If you wanted to be able to communicate with the system outside of the local area network from the mobile device you would need to establish a VPN or Remote Connection for the mobile device to the home's local area network. Furthermore, you cannot add or remove loads from keypad button program. You can only edit the levels that the existing programming is designated. Lastly, you cannot view or modify timeclock events.