Sometimes CDW drives me nuts. I'm lucky enough to have a vendor that I can rely on for accurate, quick information.
From my vendor: "Here is the message I received from you Samsung support team:
MagicInfo can support an unlimited number of LFDs, but realistically on a single normal PC about 3-400 is optimal, a heavy duty single server can go upwards of 2500, and clustered servers take over from there. This is common to most digital signage solutions.
The purchase is a single time, includes training, tech support, and updates.
We can provide the requested assistance."
So it looks like you only need one license according to Samsung.