Are these upgrades compatible with real hardware? I have a Tandy 1000 and EGA monitor I'd prefer to play the 8088 era Ultimas on.
I haven't tried this myself, but I do know the following:
The upgraded games should run in pure DOS. The only issue you're likely to have would be if the upgrade happens to add machine instructions that your CPU does not support, or if it tries to switch to protected mode (which I doubt).
The actual installation of the upgrades might be a problem, however. I remember that at least one of the upgrade patchers was actually a Win32 console application, which would not run in pure DOS (and would likely not run with your CPU). My advice would be to run the upgrade patcher on a modern computer, then transfer the resulting files to your Tandy and try running them that way.
Also, I would be careful about which options you choose when running the patcher. In particular, make sure that you choose hardware that the system you plan on running the game on actually supports; since you have an EGA monitor, you probably don't want to try running VGA graphics on it, for example. You also won't get music unless you have the appropriate hardware, either.