Override default behavior for exporting in Flexmonster to show images

Hi,

I want to use the existing functionality for exporting reports but want to allow customizeCellFunction:

report: {
    ...
    useCustomizeCellForData: true
}

This way its unfortunately not working (I tried both true and false values for the parameter). I could use maybe exportTo function with different configs and just override the handler for export to in the toolbar but I thought there may be simple configs for that? 

Update

I actually tried overriding and setting that flag to download images but it does not work and I see no images:

function () { me.flexview.exportTo("excel", { useCustomizeCellForData: false }) }

The function is definitely triggered upon downloading excel. Here is my customizeCell function which adds the images:

customizecellfunction: function (cell, data, rawdata) {
    if (!(data.hierarchy && data.hierarchy.uniqueName == "structureimage")) return;
    if (data && data.type == "header" && data.label != "") {
    let base64Img;
    cell.addClass("fm-custom-cell");
    if (data.expanded) {
        base64Img = `<i class="fm-icon fm-expanded-icon" title="Click to collapse"></i>
        <img src='data:image/png;base64, ${data.label}'/>`;
    } else {
        base64Img = `<i class="fm-icon fm-collapsed-icon" title="Click to expand"></i>
        <img src='data:image/png;base64, ${data.label}'/>`;
    }
    cell.text = `<div style="display:flex; align-items:center; font-size:12px; position:relative;">
    ${base64Img}</div>`;
}

On the screenshot attached you can see that under each ID on the left there is an empty space - thats where we expect to see the images, same as in the flexmonster view.