Please report volview issues/requests to the VolView repository here: GitHub - Kitware/VolView: Kitware VolView: an all-in-one radiological viewer!
Regarding rotation of DICOM slices, this is implemented in the Oblique View under Layouts.
Regarding image enhancements, the only ones supported right now are being able to change the window width and level. However, VolView could easily add support for custom filters via itk-wasm that it uses under the covers.