Licensing question: does coding UDXs in Python require a V Premium license?

Hi AskVertica,
I am getting this licensing questions from a customer who is on a V Express license: "Will coding V UDXs in Python require a V Premium license?"
This can be assumed from the V ALA (top of page 4, bullet 4): Python integration via Vertica prebuilt UDX.
This would also mean that a V Express license allows usage of UDXs in C++ and Java but for UDXs in R and Python a V Premium license is required.
Is this true please?
Thank you
Dieter