Yes Pro presenter will work with external Genlock.
The Benefit comes from other items -- products like out SRG series is going to provide additional features like LTC, Test Signal Outputs and the key feature is independent outputs that would allow you to individual time signal chains.
So with multiple devices that may or may not support TriLevel you can have some outputs on Tri Level and others on BB. Then each output is able to be timed separately....Thus allowing you to dial your system in. When you have non processing routers this kind of timing ensures that the signals all line up so when you switch on a router you don't disrupt downstream equipment like Projectors or recorders that don't have a genlock or timing input window.
Production Switchers have a timing window on inputs that is usually about Half a line wide centered on the incoming reference. In most cases you will just apply Reference to everything and then they will fall in the timing window. However sometimes you have to use a Scope and dial in some devices to get them to align the input correctly.
#Carbonite