As a professional and in general happy user of the sony A7RII i'd like Sony to implement the ability to use the AF-assist lamp from an external Sony flash. I use a lot this function with my Nikon being an event  and wedding photographer and i can say that sometimes it is simply essential. I'm aware of the technical problems connected with PD-af versus CD-af and on-sensor focusing and so on...but other companies did it: for example while using FL600 on Olympus bodies, the LED on the flash works as Autofocus assist lamp. Sony could also allow activation of  the normal red AF-light assist when using the LA-EA4 adapter on the A7 cameras, considering that the camera is using the adapter's PD-AF system like in a normal Dsrl.