At this point you are more likely to get a response of "What's a cablecard?" or "We don't support those anymore, we have our own great DVRs now" if you ask for one from a cable company.

(I heard that's part of why Microsoft dropped CableCard support in Windows 10 because the cable companies decided to not-so-quietly kill it and have made it almost impossible to get them if you don't already have one and have been slowly dropping support even for those that already have them.)

The cable companies can't kill it (the FCC requires them to be made available), and Tivos are still somewhat popular. It's total install base is also likely small enough that it's not worth the effort to kill it.

The FCC hasn't really enforced it well, and under the current administration isn't likely to enforce it at all. As I said, it's easy enough for them to play dumb and act like such cards don't exist and Tivo is an inferior option to their overpriced, nowadays "mandatory" DVR options. Who is going to take them to court for playing dumb?

I wonder if it works with the ATI TV Wonder Digital Cable CableCARD Tuner. I'm still running it with Windows 8 Media Center Edition w/o any problems after 7 years of continuous use!

Edit: I just saw their Supported DVR Devices and Antennas web page[1] and ATI isn't listed :(

[1] https://support.plex.tv/hc/en-us/articles/225877427

I'd give it a shot. If it works you can have them update the compatibility.