Hi @TigerCole,
Thanks for trying the Python Scripting nodes with Geospatial data! And thanks @mlauber71 for the good suggestions 
!
You are right, we currently do not support the shapely data type (or WKT in general) in KNIME. So right now the workaround is to convert this data to string, so that when we parse the Pandas DataFrame and convert it to a KNIME table we can use a type known to KNIME.
That being said, just a brief teaser here: there is a geospatial extension in the making, support will be coming to KNIME and Python in KNIME soon 
Best, Carsten