Hi,
There is no checkbox to remove an object from using DFAO unless it’s just not supported.
However, there may be a slight workaround that could help if you want to give it a try.
You can open the mesh in question up in the Mesh editor. In the Details panel to the right locate the setting for Distance Field Resolution Scale and set it to 0 and hit apply. There may be a slight amount of AO generated (At least from my tests) but this could help.
You can visualize the difference and how much affect it has on the Distance Fields by going to the viewport and selecting Show > Visualize > Mesh Distance Fields. This will show you the resolution of the meshes in the scene that are using DFAO. You should not really see your mesh isn’t really generating any Distance Fields.
Give this a shot and let me know how it goes.
Thank you!
Tim