I wanted to go over some testing that I did. In regards to triggering 2 flashes off one transceiver. there are 2 methods to do this. The first method is by having one flash on the hot shoe and one flash connected via cable.
The other method is by using a stereo splitter y adapter. I plugged this into the mono port on the transceiver then I connected 2 flashes via cables. Note i believe if you use 2 flashes with two different voltages you will have issues and it can cause damage. However if say you have 2 flashes at the same voltage or close to the same voltage you should not have issues. I tested this with a canon 580EXII and a LP160 also it was tested with a Nikon SB24 and an 580EXII all have similar trigger voltages. Rudy normally is good at this stuff so he might chime in..
Note: gadget infinity does not endorse the use of this configuration and are not responsible from any damage caused.. I also am not responsible ether.. So do at your own risk. It may be very dependent on what flashes you use.