There are a number of steps involved in doing this:

• Introduce functionality to (optionally) ophide native or open-source VDB SOPs in the newSopOperator() logic for the open-source SOP. For example, "VDB Clip (ASWF)" SOP could automatically ophide "VDB Clip" SOP. This should do nothing if the native SOP doesn't exist, except print out a warning.
• Add a set of presets to define the policy for native SOPs being hidden or not. As a starting point for introducing this mechanism and all other unifying changes, I recommend we offer just two presets initially:
  • 0: Don't hide anything, both SOPs will be visible from the tab menu (the default)
  • 1: Hide native SOPs which have obviously identical behaviour (Clip, From Polygons, etc) - (I suggest we discuss the precise list as part of the PR)
• Add an environment variable to override the preset at runtime - such as OPENVDB_OPHIDE_POLICY.
• Add an optional compiler flag to make/cmake to adjust the default preset (when not overriden by an environment variable) - such as -DOPENVDB_DEFAULT_OPHIDE_POLICY=0. This is purely as a convenience so that you don't need to set an environment variable to change the default.