public ExecuteModeType ExecuteMode {get; set;}

// Modifies the "NAME" attribute of a specified feature and then splits the feature using the provided polyline, all within a single sequential edit operation.
// perform an edit and then a split as one operation.
await QueuedTask.Run(() =>
 {
   var newName = "Modified then Split";
   var queryFilter = new QueryFilter() { WhereClause = "OBJECTID = " + objectId.ToString() };

   // create an edit operation and name.
   var op = new EditOperation
   {
     Name = "modify followed by split",         // set the ExecuteMode
     ExecuteMode = ExecuteModeType.Sequential
   };
   using (var rowCursor = layer.Search(queryFilter))
   {
     while (rowCursor.MoveNext())
     {
       using var feature = rowCursor.Current as ArcGIS.Core.Data.Feature;
       op.Modify(feature, "NAME", newName);
     }
   }
   op.Split(layer, objectId, splitLine);
   if (!op.IsEmpty)
   {
     bool result = op.Execute();
   }
   // else
   //  The operation doesn't make any changes to the database so if executed it will fail
 });