At 2.5, a new Invalidate method has been added to the MapView. The first call would invalidate the entire layer. Pass in an extent to limit invalidation to just a particular area. The second call will invalidate the extent of the features whose oids are in the lists for the two layers.
Invalidate(Layer,Envelope)
Invalidate(IReadOnlyDictionary<Layer,List<long>>)
MapView.Active.Invalidate(someLayer, null);
var dict = ...
dict[layer1] = new List<long> { 20,21,31, ...};
dict[layer2] = new List<long> { 20,21,31, ...};
MapView.Active.Invalidate(dict);