I'm guessing the answer to my question is "No", but I figured I'd ask it here in the hope that someone with more experience has a different answer.
I'm using the LabVIEW Python node to call functions that communicate (control and data) with an instrument. The Python SDK is supplied by the vendor.
As is typically done, the Python SDK has a method which instantiates an instrument object and uses the instance to open a connection. This instance can be returned from the method to be used by other methods, thereby using the same open connection.
But in the case of the LabVIEW Python node, I don't think I can use the returned instrument object in LabVIEW, since the Python node expects me to specify a return type, and I don't see what standard LabVIEW type I can use for a random instrument object.