Sorry, you need to disable all the features that depend on grid snapping, too:
additionalModules: [
{
gridSnapping: [ 'value', null ],
gridSnappingAutoPlaceBehavior: [ 'value', null ],
gridSnappingCreateParticipantBehavior: [ 'value', null ],
gridSnappingLayoutConnectionBehavior: [ 'value', null ],
gridSnappingResizeBehavior: [ 'value', null ],
gridSnappingSpaceToolBehavior: [ 'value', null ]
}
]