I figured you wouldn't be still working on your old UT mods, so your advice is more than I could have hoped for.
I wouldn't be bothered, but I think Enhanced Items was an important step forward, and with Xpickups makes the old UT look much more modern, so has become one of the mutators I always have running in every game.
Hopefully between me banging my head against it and with feedback from the UT community a solution or work-around can be made.
I thought there was a clash with the overlayer system (from looking at the logs), but apparently the SDK does not change the overlays.
Somehow maps I have been working on (adding animals) seem to work with the new SDK and Enhanced Items.
I have Enhanced Items and Xpickups in the editor package list, so something could have been added to the edited maps. (I could just load and save all my maps!)
If you do get the urge to play the old UT, try it with the newer funky updated renderers, Hi-Res texture packs, and Bloom with depth of field (even UT2K4 doesn't have that!)
I am no coder or developer, I'm just using the new SDK from the point of view of an end-user to test for stability.
If it becomes a "standard" addon to the Unreal1 engine, I'd like to know that your mod (that compliments what the SDK does for UT) will still work in the future.
If you could give Shadow (on the UT99.org forum) any of your insight into how the Enhanced Items changes UT in any way, it would be most helpful.
Possibly a lot of what your mod gives UT, could be built into the next SDK.