I did just that recently with my Dell XPS 15. My problem was that I bought an old (2013) HDX card, and installed it into a new AVID T3 chassis, but it would not update the firmware properly. I did not know anyone locally who could install the old HDX card in their desktop to update the firmware, so I had to send it to AVID for updating. Once I got it back in my AVID external enclosure, it’s functioned flawlessly. I recently installed Ultimate 2021.3 which required another firmware update, and it worked just fine.
I generally mix 28-32 tracks at a time, plus 8-10 aux tracks and a fair number of comp/EQ/delay/gate plugins. Native usually worked fine, but I chose to “upgrade” to HDX because I am now heavily into orchestral instruments and instantiating dozens of strings and wind instruments into my mixes. With many of my preferred AVID plugins now on the HDX card, I can add more virtual instruments, native effects, or extra bus processing and not get too worried about CPU bottleneck. I spent a lot of extra cash, but what the heck.
