Revert/Undo toggle

Revert is not undo.  It is revert. If there is no DOM interface  I would think the scriptlistener would generate the code you need or an action where you insert a menu item File>revert.

You can also step back some number of history states and you can suspend history state recording in a script so you only need to step back one state to undo what the script did if you do not like what a script did.

Note: Last save version may not  you where you opened the document and that History state may NO longer exists. How many History states do you keep?

Revert to the last saved version

?Choose File > Revert.

Note: Revert is added as a history state in the History panel and can be undone.

I hope I have understood the question well

These are 2 scripts

one and to return history back

more to go history ahead

I put a shortcut button so I can use it quickly

story back

#target photoshop
// Step back
var docRef = app.activeDocument
var savedLayer = docRef.activeLayer
try{
var idslct = charIDToTypeID( "slct" );
    var desc3 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref1 = new ActionReference();
        var idHstS = charIDToTypeID( "HstS" );
        var idOrdn = charIDToTypeID( "Ordn" );
        var idPrvs = charIDToTypeID( "Prvs" );
        ref1.putEnumerated( idHstS, idOrdn, idPrvs );
    desc3.putReference( idnull, ref1 );
    executeAction( idslct, desc3, DialogModes.NO );
}
catch(err)
{}

story ahead

#target photoshop
// Step forward
var docRef = app.activeDocument
var savedLayer = docRef.activeLayer
try{
    var idslct = charIDToTypeID( "slct" );
    var desc5 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref2 = new ActionReference();
        var idHstS = charIDToTypeID( "HstS" );
        var idOrdn = charIDToTypeID( "Ordn" );
        var idNxt = charIDToTypeID( "Nxt " );
        ref2.putEnumerated( idHstS, idOrdn, idNxt );
    desc5.putReference( idnull, ref2 );
executeAction( idslct, desc5, DialogModes.NO );
}
catch(err)
{}