Because N1MM only supports serial connections, enabling programs like FLrig would cause conflicts. SimpleRIGMux aims to map FLrig conveniently to a virtual serial port using hamlib rigctlcom and com0com, allowing it to work in conjunction with programs like N1MM. I've created a very rough "test test test" version, and I hope to receive some feedback.
Testing/Usage Tutorial
Unzip the archive and run the SimpleRIGMux.exe program inside.
If you do not have com0com installed on your computer, the program will prompt you to install it and then exit.


[An installation wizard will appear, and you should click the "Next" button repeatedly until the window disappears. Then, re-run SimpleRIGMux.exe. The first time you run it, it may be slower; do not start multiple instances at once (I don't know what will happen).]
Start and configure FLrig to connect to the radio station (Note: The port for the XML-RPC service should be the default, 12345. If you don't know what this means, just ignore it).
Click the "Start" button in the SimpleRIGMux window (if the button is green, it means that the program is running).
Open N1MM and add the ExpertSDR radio, configuring the ports according to the instructions provided by SimpleRIGMux.

- ... Is everything complete? (If not, you can click on the menu bar (Window-)>(Please provide the log and screenshots in this thread)
What other ways can I play?
Currently, the only viable option I can think of is to use this device to connect FLRig to Omnirig, allowing HDSDR/CW Skimmer and other applications to also work with FLRig. The ideal outcome would be to completely integrate FLRig, Omnirig, Hamlib, and serial ports (like N1MM) without any concerns about serial port conflicts.
If you have any further suggestions, please provide them below :-)