Smart render in Vegas for Panasonic H-280 hard disk camcorder

I spent few evenings figuring out why vegas always recompresses MPEG2 video from my camcorder, instead of using Smart Render. First, both project and encoder must be set to video size 704×576 pixels, with upper field first interlace (note, that changing encoder template is only possible with Vegas Pro). And the magic setting that will allow smart render is to set Maximum Bitrate for encoder to exactly 9542800 bits/s.