The Delete Faces Modifier is a C++ modifier similar to the DeleteMesh modifier in Max except it has several controls and options. Instead of always deleting the incoming mesh at the currently selected sub-object level, it gives you several options for what faces to delete:

• By Selected Faces
• By Selected Vertices
• By Smoothing Groups
• By MaterialIDs
• By Face IDs
• By Polygon IDs

This plugin is available for 3ds Max 2015+.

Note: For 3ds Max 2016, you may need to install Microsoft Visual C++ 2013 Redistributable (x64) from the Microsoft website if it is not already installed.

CHANGELOG

Version 2.12

•  Added option to Skip Selected Faces.
• Fixed bug in Use Selected Vertices. 

Version 2.11

•  Fixed faces being skipped when By Polygon is on and the faces in polygon were not planar.

Version 2.1

•  Added support for Max 2018.
  
• Fixed some problems with Delete Faces.
• Fixed isolated vertices not being deleted.
• Added button in Custom Attribute to delete the rollout when it persists after the modifier list has been collapsed.

Version 2.0

•  Added Support for 3ds Max 2015.
• Converted to C++ plugin with speed increases.
• Added new option to choose by smoothing groups based on: Match ANY, Match All or Match None.
• Added option to choose material ID or exlude by material ID.
  

Version 1.0

 * Initial Release. 

Known Issues

• In 3ds Max 2017+ an object using this modifier is no longer selectable in the viewports. Workarounds include selecting via the Scene Explorer or to add a Vol. Select above the Delete Faces modifier. I am looking into fixing this issue.