Toggle selection script

I‘ll have another stab at this as I don’t understand this script behaviour:

Basically two commands

var id123 = charIDToTypeID( "Invs" );
executeAction( id123, undefined, DialogModes.NO );

 Inverse selection (not inverse pixel colour) - works fine

show/hide the crawling ants selection by toggling it:
 

app.runMenuItem(stringIDToTypeID("toggleEdges"));

toggles the visibility of the current selection on/off

Yay! Two tiny bits of code work just fine.

However... they don’t run one after another, you can’t inverse the selection and then hide the selection. I’ve tried. I have no idea why. I’ve added a delay, separate scripts, separate actions, toggle the selection twice. No dice.

I’m stumped as to why the two bits of code won’t work sequentially. Any ideas? 
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