Even though I had already made my ugly cuts for Beloved, I had a bunch of boards (both pink and white beadfoam) left to cut for tombstones, so I tried it late on Sunday. To thoroughly test the ease of use of this technique, I had a gin martini first. Now as fun as power tools and alcohol, but I figured a sharp blade would run a close second.
It worked like a champ on both types of board. While it may take longer, it is by far the best result for straight cuts.
Freakin' smart-ass. Oh, and thanks, Steve-O.