Specific chunks cannot be tessellated or have the triangle increased in this manner. If you need a specific setup it would probably be better to either use the Custom FBX Import option in the Destructible Mesh Editor or you can setup a Blueprint that has pre-configured fractures. Then you can spawn and destroy how you see fit. This also will allow you much greater control for instances where you need it. There is more setup required though.
Also, I’ve recently added a Wiki Troubleshooting and Tips page for Destructibles here: https://wiki.unrealengine.com/Destructible_Troubleshooting_Guide
It may not answer very specific questions in most cases, but these are the more common questions that are asked regarding Destrucitble Meshes.
Feel free to ask any questions and I’ll help where I can. If you would like to see something added that could be useful for others let me know and I’ll try to get it up on the page.