Resizing selection box only triggers immediate chunk loads when mouse button is released.

src/mcedit2/editortools/select.py

@@ -263,6 +263,7 @@ class SelectionTool(EditorTool):
                 command.setText(self.tr("Resize Selection"))
             self.editorSession.undoStack.push(command)
             self.updateNodes()
+            self.selectionNode.loadImmediateChunks()
 
     def mousePress(self, event):
         self.boxHandleNode.mousePress(event)

src/mcedit2/rendering/selection.py

@@ -157,7 +157,9 @@ class SelectionScene(scenenode.Node):
         self.renderSelection = selection & NonAirMaskSelection(self.dimension, selection)
         self.groupNode.clear()
         self._loader = None
-        if selection.chunkCount < 16:
+
+    def loadImmediateChunks(self):
+        if self.selection.chunkCount < 16:
             exhaust(self.loadSections())
 
             self.loadTimer.setInterval(333)