Using an extrusion depth of 0 with Three.js results in the normals of exported objects being flipped inside-out. By supplying an extrusion depth > 0, the standard Blender boolean modifiers should work as expected.
For the current version of the exporter, you can still use Blender 2.8+ if you first flip the normals of meshes that have a depth of 0. I tested with Blender 3.4.
Using an extrusion depth of 0 with Three.js results in the normals of exported objects being flipped inside-out. By supplying an extrusion depth > 0, the standard Blender boolean modifiers should work as expected.
For the current version of the exporter, you can still use Blender 2.8+ if you first flip the normals of meshes that have a depth of 0. I tested with Blender 3.4.