SUCCESS!!
Ok so I tested it, and it worked perfectly. Unfortunately it is again something that some people will not be able to accomplish. (Khaine isn't kidding about people incapable of simply copying files out of a zip into the mod folder. I spent a few hours the other day with someone on the exact same thing.)
Step 1 - Copy/rename serverconfig.xml. For this example I am using "a20serverconfig.xml". You want the file different so it isn't reset with an update.
Step 2 - Edit the file to replace the following section starting at line 40.
<!-- Folder and file locations -->
<property name="AdminFileName" value="serveradmin.xml"/> <!-- Server admin file name. Path relative to the SaveGameFolder -->
<!-- <property name="UserDataFolder" value="absolute path" /> --> <!-- Use this to override where the server stores all generated data, including RWG generated worlds. Do not forget to uncomment the entry! -->
<!-- <property name="SaveGameFolder" value="absolute path" /> --> <!-- Use this to only override the save game path. Do not forget to uncomment the entry! -->
Your new section will look something like this...
<!-- Folder and file locations -->
<property name="AdminFileName" value="serveradmin.xml"/> <!-- Server admin file name. Path relative to the SaveGameFolder -->
<property name="UserDataFolder" value="D:\SaveGames\a20" /> --> <!-- Use this to override where the server stores all generated data, including RWG generated worlds. Do not forget to uncomment the entry! -->
<property name="SaveGameFolder" value="D:\SaveGames\a20\Saves" /> --> <!-- Use this to only override the save game path. Do not forget to uncomment the entry! -->
Step 3 - Create the folder D:\SaveGames\a20\Mods
Step 4 - Go to your Steam Library, Right-click on 7 Days, and choose Properties.
Step 5 - Add the following to your launch options. -configfile=a20serverconfig.xml (Again, your file will vary on what you name it. This is the example.)
Step 6 - Close the window, and start the game.
Now I can just use the config file in each separate folder, and tell the client where to go for all the data. No symlinks required.