[stargazer]

I’m on a MacPro5,1 (4,1 firmware upgraded to 5,1, Early 2009).
Still on High Sierra, 10.13.6, due to my non Metal compatible graphics card (NVIDIA GeForce GT 120).
Since I heard successful stories about upgrading to PT 2021.3 on similar rigs, I’d like to try that, but also be able to roll back to 2020.11 if it doesn’t work.

So, will 2020.11, or some other previous version, still work with the 2021.3 firmware updated HDX card?

Also, at the moment I’m using a Fast Track Solo, while waiting for a new interface, since my HD Omni died recently.
Will the absence of an HD compatible interface affect the FW upgrade of the HDX card, since an interface is needed to make the card available to Pro Tools?