How to export a png with single IDAT chunk using Fireworks script?

Question

I am able to export 32 bit PNG files using JavaScript Fireworks (JSF) using following export parameters:

exportFormatOptions:{
    name:"PNG size 440",
    xSize:440,
    ySize:440,
    cropTop:0,
    crop:false,
    sorting:"none",
    exportFormat:"PNG",
    paletteEntries:null,
    numGridEntries:6,
    ditherPercent:100,
    jpegSmoothness:0,
    jpegSubsampling:0,
    jpegSelQuality:90,
    percentScale:100,
    progressiveJPEG:false,
    interlacedGIF:false,
    animAutoCrop:true,
    localAdaptive:true,
    webSnapAdaptive:false,
    lossyGifAmount:0,
    jpegSelQualityEnabled:false,
    jpegSelPreserveButtons:false,
    savedAnimationRepeat:0,
    numCustomEntries:0,
    numEntriesRequested:0,
    paletteTransparency:"none",
    webSnapTolerance:14,
    jpegSelPreserveText:true,
    animAutoDifference:true,
    macCreator:"",
    macFileType:"",
    colorMode:"32 bit",
    paletteMode:"adaptive",
    paletteInfo:null,
    ditherMode:"none",
    jpegQuality:80,
    cropLeft:0,
    cropBottom:0,
    cropRight:0,
    applyScale:true,
    useScale:false,
    optimized:true,
    frameInfo:[]
}

But it exports the image data in multiple IDAT chunks, depending on the resolution.

Eg. a 440x440 PNG has 10 chunks, a 160x160 PNG has 5 chunks, etc. How can I control the number of chunks the image data gets exported into? Can I add some export options parameter in the script?