I produced an Excel file some time ago which enables you to work out the settings for the Tempo multipoint controller to give the appropriate jazzy feel in playback. It is based on Marsu's original method, but the spreadsheet does the calculations for you.
It is in the Scripto at
http://nwc-scriptorium.org/helpful.html#NWCFiles Scroll down to the bottom of the section and you will find a link to a file called Jazzyquavers.zip.
The file also works very well for giving a lilt to folk tunes, such as jigs and hornpipes. Quaver pairs in hornpipes are usually played dotted - approx 2:1 ratio and the first quaver of a quaver triplet in a jig is usually "lent on" a little borrowing some time from the middle one. The amount depends on the particular tradition, more in a Northumbrian jig than an Irish jig for example.
Geoff