Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Freeze
FIELDLAYER_PROXIMITY_FORCE_SAVEParameter: Clear
FIELDLAYER_PROXIMITY_FORCE_CLEARParameter: Mode
FIELDLAYER_PROXIMITY_MODEParameter: Auto-Update
FIELDLAYER_PROXIMITY_DYNAMIC_UPDATEParameter: Subfields Only
FIELDLAYER_PROXIMITY_SELF_AGGREGATEParameter: Optimize Search Tree
FIELDLAYER_PROXIMITY_USE_INPUT_CRCParameter: Radius
FIELDLAYER_PROXIMITY_RADIUSParameter: Effect Strength
FIELDLAYER_PROXIMITY_EFFECT_RATIOParameter: Radius
FIELDLAYER_PROXIMITY_FIELDS