We released version 3.0 of the Silhouette Plugin for MTC. This version adds the Silhouette Portrait along with a new cutting option "Cut by Knife Point", which will allow you to move your knife around the mat and choose where to cut your project.
Remember: To use the Print and Cut features on any Silhouette machine, always work in Landscape mode in MTC.
If using the Portrait machine for a print-and-cut, make sure to use the "Silhouette Cameo" registration marks when printing. Also, use the "Silhouette Mat" in MTC (the 8.5x12" mat)
Download here: http://www.make-the-cut.com/Download.aspx
(Scroll to the bottom-half of the page)
Thank you to @corwins
for sending me her Portrait machine in order to figure it out/add it!
I don't often test my code... But when I do, I do it in production.