System76 make linux-based computers, and they specifically ship them with the IME disabled. I know that’s not exactly what you ask for, but it’s similar in nature
What’s the downside of having it disabled?
To the average user: literally nothing.
The downside of disabling it is the chance of bricking your expensive silicon, as the drivers to it are mysteriously inaccessible to the operating system, but I literally can’t think of anything else to add once it’s already down. It’s not-end user facing, there’s no API for it, it’s basically just there to be a firmware back door for the NSA and possibly extremely skilled foreign hackers. It doesn’t affect the actual processing layer of the chip at all IIRC.
I actually considered a thelios or whatever they call their desktop systems are called but, the fact that their motherboards don’t support liquid cooling blocks was a turn off for me. Id get a laptop but they are so very expensive. If only I had the money, it would be my first choice however. Certainly now that Linux gaming has become just as good if not even a better experience than on wendoze.