I could obtain a "second hand" workstation HP Z640 with a Quadro M4000 (8GB, Maxwell) inside (CPU: Xeon E5 2640v4 - 10core+10HT).
I am aware that this is not the latest technology, but yet my question: should I be able to process Python tasks on a reasonable basis with this machine?

I've never seen any definitive statement from the developer about what the minimum card supported is.

Comments in the forum state that minimum 6GB of VRAM is recommended along with a good amount of system RAM >=8GB and sufficient storage space for a pagefile of 32GB starting size.

And you have to use a minimum Nvidia driver level of >450.82 to get at least CUDA11.2 capability used on the Quadro M4000.

Recommend the latest Nvidia 515 series used.