Can the tunderbolt 3 card for Z8 be used with eGPU (external GPU) boxes ?

[Alex2018]

   I know it is possible to buy a thunderbolt 3 card to add up thunderbolt capabilities through USB-C ports to the Z8 G4 workstations (https://www.hp.com/us-en/shop/pdp/hp-thunderbolt-3-pcie-2-port-i-o-card).

   I don't know if HP still sell them for real (looks like it), but anyway I found a supplier even in Europe (where I am) that does have them.

    I have a graphic card in the Z8, and I am getting (already ordered) a second one of  the same model (a two slot card), that I plan to temporarily use with an external box as "eGPU" with a laptop, since  for work I am away from my workstation, while waiting for a new graphic/computation card model I want to come out and get lower in price (it has been announced, but the announced pricing is a killer).

     The idea is when I can get back to my workstation in few months, I would put the second graphic/computation card  in the Z8 while leaving the first in - they are NVIDIA graphic cards I use for CUDA, as indicated, same model, although they do not support NVLink, and then, hoping in the meantime the new cards are gone a bit down a bit in price, get a new one, and use that new one with as eGPU with the laptop.

     When I am back with access to the desktop, I think it would be in theory  possible to take the new card out of the external box and put it inside the Z8, and the power adapter should be OK, but there will not be enough power cables available, and the space risks to become cramped (the fan is already noisy, although the temperatures with one card are not high) and the air circulation will probably suffer (and temperatures inside the computer increase).

     So, the doubt I have is, it is possible to use the thunderbolt 3 card for the Z8 G4 to use an eGPU (GPU through an external box with thunderbolt 3 USB-C connection) as additional GPU for the system ?
     Of course the performance over the USB-C Thunderbolt 3 would be lower than if it the new card was inserted directly in a slot (though anyway, my Z8 G4 is PCIe 3, the new card would be PCIe4), but there would be a number of advantages to that configuration, so I would like to know if anybody has a clue about whether what I am thinking to do is possible (in theory, I know it is and, but it depends from the Z8 G4 hardware).

  Thanks in advance for any help