Dan, ordinarily I do not trim and just leave a large border as you suggest. Thank you for the advice.
The issue is that I need for the prints to fit into an 11x14 portfolio box. Since Canson doesn't offer Platine in 11x14 the simplest option I can see is trimming 11x17 sheets. The actual image sizes are approximately 8x12 so I will have plenty of border area
Geraldo and Rand, you make an excellent points regarding dust, paper debris and the printer, thank you both for your advice.
I think I can print on 11x17 and then trim to 11x14 by inserting the paper into the trimmer in such a way that the printed surface remains outside of the Rototrim and I just trim the one border. That way I hopefully won't scratch or damage the printed surface. I print using Lightroom and I think I can set up the margins etc to make it easy to trim.