Haxe Map Memory Cleanup Issue - actionscript-3

Question

So I have been using Haxe for a while and it has occurred to me recently that I don't really get what happens on some other the non-flash targets as far as memory cleanup. I mean 'new'ing everything and dumping it by setting references to null gives me this feeling that there are memory leakages, but I can't seem to find the documentation I'm looking for.
Specifically I use dictionaries/maps a decent amount. Like this:
var items:Map<String, MyObject> = new Map();
items.set("someKey", new MyObject(args...));
// Later
items["someKey"].doSomething();
items["someKey"].setVal(2);
...
// When Finished
items.remove("someKey");
The last line there just dumps my object somewhere into oblivion and hopefully gets garbage collected (at least on the Flash target).
I put together a little program just to see the cleanup in action on Flash/Neko and then change it for other targets, but I am failing to even see the cleanup on the Flash Neko target. Here is the project code:
package;
import openfl.display.Sprite;
import openfl.events.Event;
import haxe.ds.StringMap;
import openfl.events.KeyboardEvent;
import openfl.ui.Keyboard;
class Main extends Sprite
{
private var keypressID:Int;
private var itemID:Int;
private var dict:StringMap<Sprite>; // Using this since I read Map<String, T> just compiles to StringMap<T>.
public function new()
{
super();
addEventListener(Event.ENTER_FRAME, init);
}
private function init(event:Dynamic):Void
{
removeEventListener(Event.ENTER_FRAME, init);
// Entry point.
keypressID = 0;
itemID = 0;
dict = new StringMap();
stage.addEventListener(KeyboardEvent.KEY_UP, keyPress);
}
private function keyPress(event:Dynamic):Void
{
if (Std.is(event, KeyboardEvent) && cast(event, KeyboardEvent).keyCode == Keyboard.A)
{
trace('ID: $keypressID - Adding Item');
keypressID += 1;
for (i in 0...10000)
{
itemID += 1;
dict.set('$itemID', new Sprite());
}
}
else if (Std.is(event, KeyboardEvent) && cast(event, KeyboardEvent).keyCode == Keyboard.R)
{
trace('ID: $keypressID - Removing Items');
keypressID += 1;
removeItems();
}
// Force garbage collector to run.
else if (Std.is(event, KeyboardEvent) && cast(event, KeyboardEvent).keyCode == Keyboard.C)
{
trace('ID: $keypressID > Starting GC');
keypressID += 1;
forceGarbageCollection();
}
}
private function removeItems()
{
trace('ID: $keypressID > Remove All Item');
for (val in dict.keys())
{
dict.remove(val);
}
dict = new StringMap();
}
private function forceGarbageCollection():Void
{
neko.vm.Gc.run(true); // This does not work.
}
}
I run this on Windows and under task manager, my neko process only grows and never shrinks. Its gets up to 500MB quick when hitting 'A'. I then 'R' to remove all references to the items, but they never get collected it seems even when I force the GC.
I also tried storing openfl.util.Timer objects with event listeners attached to them to do traces and they never seem to get collected either. They just keep tracing. Now I suspect that may be because of the event listener reference, but am sure I have seen that trick in other AS3 memory leak tracking code.
Am I missing something or doing something wrong?
Edit:
I have modified the above question to reflect this, but I was mistaken about Flash player. I did get the memory to be reclaimed when running in the Flash player using flash.system.System.gc(); It seems the problem may be specific to neko which my question still addressed.