Thank you for these cool modifications.

You are right.
search didn't work because of extra whitespaces .
LGraphCanvas.prototype.renderInfo = function (ctx, x, y)
LGraphCanvas.prototype.renderInfo = function( ctx, x, y )

Now I find it. :)

I usually prefer to have different versions of same node, But I gave it a try.
I added your modification as you showed, but couldn't see any difference.("save as" window pops up with empty name field)


Anyways, I change your code a bit.
Now if you press the save button and alt key , it saves on existing node file without confirmation.
otherwise works like before.

Editor.prototype.onSaveButton = function (e)
{
	if (this.graph.blocked) return;
	var saveFilePath="";
	// var saveFilePath = moi.filesystem.getSaveFileName( lang.getTranslation('Save as')+' ..',  lang.getTranslation('MoI Nodeeditor files')+' (*.nod)|*.nod' );
	// if (e.altKey) {saveFilePath = moi.filesystem.getSaveFileName(lang.getTranslation('Save as') + '..', lang.getTranslation('MoI Nodeeditor files') + ' (*.nod)|*.nod',lang.getTranslation(this.graph.filename));}
	
	if (e.altKey) {saveFilePath = lang.getTranslation(this.graph.filename);}
	else {saveFilePath = moi.filesystem.getSaveFileName( lang.getTranslation('Save as')+' ..',  lang.getTranslation('MoI Nodeeditor files')+' (*.nod)|*.nod' );}

	if ( !saveFilePath ) return false;
	if ( this.graph.status !== LGraph.STATUS_STOPPED ) this.onPlayButton();
	var file = moi.filesystem.openFileStream( saveFilePath, 'w' );
	file.writeLine(LiteGraph.JSONprettify(this.graph.serialize(), {"indent":"	", 'maxLength':150}));
	file.close();
	this.graph.filename = saveFilePath;
	this.graph.setDirtyCanvas(true,true);
}