Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Phase
MBLUR_PHASE
Parameter: Density
MBLUR_DENSITY
Parameter: Samples
MBLUR_SAMPLES
Parameter: Sample Radius
MBLUR_BLUR
Parameter: Weighted Trails
MBLUR_TRAILS
Parameter: Geometry Deformation
MBLUR_MESHTRACK