I know this is an old thread but this may help someone.
I’ve had the same issue. In Reaper I ended up routing OHs to a non existent channel on my main drum track and loading another instance of ezd3 on a separate track with only cymbals no other drums or hats. It’s not CPU efficient but it completely avoids any unwanted bleed for mixes that has no bleed control.
You can then make a main drum bus to group it all together.
Reply To: Removing bleed from OHs version: 3.0.6 Operating system: Windows 11