https://discourse.threejs.org/t/three-bvh-csg-a-library-for-performing-fast-csg-operations/42713
claims even 100x performance for booleans
look at this smooth realtime boolean 
https://gkjohnson.github.io/three-bvh-csg/examples/bundle/simple.html
It is dependant on threejs, but is interesting to explore nevertheless
https://github.com/gkjohnson/three-bvh-csg
@z3dev got my first email from this user group and daily digest. That is great news that you got this working.
https://discourse.threejs.org/t/three-bvh-csg-a-library-for-performing-fast-csg-operations/42713
claims even 100x performance for booleans
look at this smooth realtime boolean
https://gkjohnson.github.io/three-bvh-csg/examples/bundle/simple.html
It is dependant on threejs, but is interesting to explore nevertheless
https://github.com/gkjohnson/three-bvh-csg
