Going to answer my own question here since it might help others that are new to Python in 3dsmax... I did not know that you are supposed to use the SDK documentation to interprete how to use MaxPlus. In the SDK docs I can see that the string argument is filled with the contents of User Defined Props.
MAXSCRIPT DOCS
getUserPropBuffer <node>
Retrieves the entire user property buffer as a string containing all the user property settings. This is effectively the contents of the User Defined Properties box in the 3ds Max Object Properties dialog.
PYTHON API REFERENCE
def GetUserPropBuffer | ( | | self, |
| | | args |
| ) | | |
GetUserPropBuffer(INode self, WStr buf)
SDK REFERENCE
virtual void GetUserPropBuffer | ( | MSTR & | buf | ) | |
| pure virtual |
Remarks This method allows access to the entire user defined property text buffer. Parameters
buf | The buffer to hold the user defined property text. |