Looks like nobody else has an opinion. So, I'll jump in here. It depends on which Summa plotter you have. I have a D120. I think it plots between 4" and 47.2". Your D140 is larger. If you can print from your version of Flexi, then why not print and plot from Flexi? I do it all the time with my Edge 2 and Summa. And, if you exported the file from Flexi to Gerber software, I don't think Gerber software can put Summa registration marks on the print. Flexi can put the Summa registration marks on the print. Hope I'm not reading your question wrongly.