K3 emulation in the RCForb server software is to run external programs and hardware that see the rig. In my case, at the remote site, the emulator port talks to LP Bridge, which creates a bunch of ports that look like a direct connection the K3. It runs NaP3, a SteppIR DB42 controller, N1MM (when used at the remote site)and CW Skimmer. If you are just connecting your rig to the server with none of those other things, there is no need for emulation.
At the control side, the client software can talk directly to the server, and if you have everything set up right, your radio will be operable by anyone with client software and an internet connection. The client has two emulator that look like a K3 that LOGic will see. Typically, I have one emulator (COM44) connected to LOGic, and the other one can be used for WSJT-X or MMTTY. I added the K3/0 Mini, which is a simple USB connection that the client software uses.
It sounds like a kluge, but after burning up bunch of brain cells making it all work, it actually works!
One caution...I use Client version 0.8 (not 0.9) since one of the K3 functions, RIT CLEAR is busted in 0.9 and I use that a lot in contests. I reported it over a year ago, and no joy getting them to fix it.
Ron
N6IE