Now that AMD Catalyst 15.5 has been released I attempted to try this version with my configuration.
Radeon HD 7000
DisplayPort connected to a U2415b DELL MST Hub Monitor (chained to another DELL 24)
DVI connected to another DELL 24
Only 2 monitors are detected. (1 of the DisplayPort monitors is detected and the DVI monitor)
Missing from the Catalyst Control Center is the DisplayPort screen.
When I have 14.12 installed, (where all my monitors are detected) shows the following screen shot:
With driver versions 15.3 AND 15.5 CCC does NOT show this information and 3 monitors in the configuration I describe above does NOT work.