variable font progression

This would override master page text frames containing an auto number. Note that if the page number is not on its own layer its stacking order might change.

//an array ids for masterpage textframes containing auto page numbers
var nid = getPageNumberID("^#")
 
var p = app.documents[0].pages.everyItem().getElements();
var mpi;
for (var i = 0; i < p.length; i++){
    mpi = p[i].masterPageItems;
    for (var j = 0; j < mpi.length; j++){
        if (mpi[j].constructor.name == "TextFrame" ) {
            if (checkItem(nid, mpi[j].id)) {
                mpi[j].override(p[i])
            } 
        } 
    }
};   

/**
* Gets the ID of the found text’s parent frame 
* @ param text to search for 
* @ return an array of text franme ids
*/
function getPageNumberID(fp){
    app.findTextPreferences = app.changeTextPreferences = app.findChangeTextOptions = null;
    app.findChangeTextOptions.properties = { 
        includeMasterPages:true} 
    app.findTextPreferences.findWhat = fp;
    var res = app.activeDocument.findText()
    var ids=[]
    for (var i = 0; i < res.length; i++){
        ids.push(res[i].parentTextFrames[0].id)
    };   
    return ids
}

/**
* Checks if an item is in an array
* @ param the array to check 
* @ param the item to look for 
* @ return true if the item is in the array 
* 
*/
function checkItem(a, obj) {
    for (var i = 0; i < a.length; i++) {
        if (a[i] === obj) {
            return true;
        }
    }
    return false;
}