Staff lines under title (Real Book style)

Don't use a Title box. Make the first line of your score a single measure and make the clef, time signature and bar lines invisible. Add a text entry to the rest in this bar, increase its size, turn off Autoplacement and move it to suit. Generally play around until you are happy then save as a blank score or template for future use. The attached file is just a quick play around to give you an idea of what is possible - there will be a better way to do it, no doubt.
JazzTitle.mscz

You could simply move the title down to covert the first staff. But you'd still want to hide the clef/key/meter. Then maybe add a section break after the first measure so only that measure is on the line, and the next measure starts at 1 again.