Hi Bobk81,
To use the second monitor, you should set the view setting View > "Use All Displays in Full Screen". This is the same as the VMX config option:
gui.fullScreenOnAllHostDisplays="TRUE"
Make sure your Fusion preference Display > Full Screen is set to "Resize the virtual machine to fit the screen", and toggle full screen.
If that still doesn't work, you can also try specifying these four config options together to override the monitor autodetect settings. (But it sounds like you already did, and it didn't help)
svga.autodetect="FALSE"
svga.numDisplays="4"
svga.maxWidth="3840"
svga.maxHeight="2160"
You can also try setting your screen resolutions manually, by setting the Full Screen preference to "Center the virtual machine in the screen", and Single Window preference to "Stretch the virtual machine in the window". Then use the VMwareResolutionSet.exe binary installed with Tools. With these settings, your guest topology should not change when you toggle between single window and full screen mode. If you can set the modes, then you can see their layout in the single window.
"C:\Program Files\VMware\VMware Tools\VMwareResolutionSet.exe" 0 2 32 , 0 0 1920 1080 , 1920 0 1920 1080
"C:\Program Files\VMware\VMware Tools\VMwareResolutionSet.exe" 0 2 32 , 0 0 1280 1024 , 1280 0 1920 1080
Meaning respectively, "set a topology of 1920x1080+0+0, 1920x1080+1920+0", and "set a topology of 1280x1024+0+0, 1920x1080+1280+0".
Matt